Rohde & Schwarz FSP3, FSP31, FSP-B9, FSP-B10, FSP7 Operating Manual

R&S

®

FSP

Spectrum Analyzer

Operating Manual

1164.4556.12 – 06

Operating Manual

Test & Measurement

The Operating Manual describes the following R&S®FSP models and options:

' R&S FSP3 (1164.4391K03)
' R&S FSP7 (1164.4391K07)

R&S FSP13 (1164.4391K13)

'
' R&S FSP30 (1164.4391K30)
' R&S FSP30 (1164.4391K39)
' R&S FSP31 (1164.4391K31)
' R&S FSP40 (1164.4391K40)
' R&S FSP-B6 (1129.8594.02)
' R&S FSP-B9 (1129.6991.02)
' R&S FSP-B10 (1129.8042.03)
' R&S FSP-B16 (1129.8042.03)
' R&S FSP-B21 (1155.1758.03)
' R&S FSP-B28 (1162.9915.02)

© 2009 Rohde & Schwarz GmbH & Co. KG

81671 Munich, Germany

Printed in Germany – Subject to change – Data without tolerance limits is not binding.

®

R&S

is a registered trademark of Rohde & Schwarz GmbH & Co. KG.

Trade names are trademarks of the owners.

The following abbreviations are used throughout this manual:

®

FSP is abbreviated as R&S FSP.

R&S

Basic Safety Instructions

Always read through and comply with the following safety instructions!

All plants and locations of the Rohde & Schwarz group of companies make every effort to keep the safety
standards of our products up to date and to offer our customers the highest possible degree of safety. Our
products and the auxiliary equipment they require are designed, built and tested in accordance with the
safety standards that apply in each case. Compliance with these standards is continuously monitored by
our quality assurance system. The product described here has been designed, built and tested in
accordance with the attached EC Certificate of Conformity and has left the manufacturer’s plant in a
condition fully complying with safety standards. To maintain this condition and to ensure safe operation,
you must observe all instructions and warnings provided in this manual. If you have any questions
regarding these safety instructions, the Rohde & Schwarz group of companies will be happy to answer
them.

Furthermore, it is your responsibility to use the product in an appropriate manner. This product is designed
for use solely in industrial and laboratory environments or, if expressly permitted, also in the field and must
not be used in any way that may cause personal injury or property damage. You are responsible if the
product is used for any intention other than its designated purpose or in disregard of the manufacturer's
instructions. The manufacturer shall assume no responsibility for such use of the product.

The product is used for its designated purpose if it is used in accordance with its product documentation
and within its performance limits (see data sheet, documentation, the following safety instructions). Using
the product requires technical skills and a basic knowledge of English. It is therefore essential that only
skilled and specialized staff or thoroughly trained personnel with the required skills be allowed to use the
product. If personal safety gear is required for using Rohde & Schwarz products, this will be indicated at
the appropriate place in the product documentation. Keep the basic safety instructions and the product
documentation in a safe place and pass them on to the subsequent users.

Observing the safety instructions will help prevent personal injury or damage of any kind caused by
dangerous situations. Therefore, carefully read through and adhere to the following safety instructions
before and when using the product. It is also absolutely essential to observe the additional safety
instructions on personal safety, for example, that appear in relevant parts of the product documentation. In
these safety instructions, the word "product" refers to all merchandise sold and distributed by the Rohde &
Schwarz group of companies, including instruments, systems and all accessories.

Symbols and safety labels

Notice, general
danger location

Observe product
documentation

ON/OFF supply
voltage

Caution
when
handling
heavy
equipment

Standby
indication

Danger of
electric
shock

Direct current
(DC)

Warning!
Hot surface

Alternating current
(AC)

PE terminal Ground Ground

terminal

Direct/alternating
current (DC/AC)

Device fully protected by
double (reinforced) insulation

Be careful when
handling
electrostatic
sensitive
devices

1171.0000.42-05.00 Page 1

Basic Safety Instructions

Tags and their meaning

The following signal words are used in the product documentation in order to warn the reader about risks
and dangers.

indicates a hazardous situation which, if not avoided, will result in death or
serious injury.

indicates a hazardous situation which, if not avoided, could result in death or
serious injury.

indicates a hazardous situation which, if not avoided, could result in minor or
moderate injury.

indicates the possibility of incorrect operation which can result in damage to
the product.
In the product documentation, the word ATTENTION is used synonymously.

These tags are in accordance with the standard definition for civil applications in the European Economic
Area. Definitions that deviate from the standard definition may also exist in other economic areas or
military applications. It is therefore essential to make sure that the tags described here are always used
only in connection with the related product documentation and the related product. The use of tags in
connection with unrelated products or documentation can result in misinterpretation and in personal injury
or material damage.

Operating states and operating positions

The product may be operated only under the operating conditions and in the positions specified by the
manufacturer, without the product's ventilation being obstructed. If the manufacturer's specifications are
not observed, this can result in electric shock, fire and/or serious personal injury or death. Applicable local
or national safety regulations and rules for the prevention of accidents must be observed in all work
performed.

1. Unless otherwise specified, the following requirements apply to Rohde & Schwarz products:
predefined operating position is always with the housing floor facing down, IP protection 2X, pollution
severity 2, overvoltage category 2, use only indoors, max. operating altitude 2000 m above sea level,
max. transport altitude 4500 m above sea level. A tolerance of ±10 % shall apply to the nominal
voltage and ±5 % to the nominal frequency.

2. Do not place the product on surfaces, vehicles, cabinets or tables that for reasons of weight or stability
are unsuitable for this purpose. Always follow the manufacturer's installation instructions when
installing the product and fastening it to objects or structures (e.g. walls and shelves). An installation
that is not carried out as described in the product documentation could result in personal injury or
death.

3. Do not place the product on heat-generating devices such as radiators or fan heaters. The ambient
temperature must not exceed the maximum temperature specified in the product documentation or in
the data sheet. Product overheating can cause electric shock, fire and/or serious personal injury or
death.

1171.0000.42-05.00 Page 2

Basic Safety Instructions

Electrical safety

If the information on electrical safety is not observed either at all to the extent necessary, electric shock,
fire and/or serious personal injury or death may occur.

1. Prior to switching on the product, always ensure that the nominal voltage setting on the product
matches the nominal voltage of the AC supply network. If a different voltage is to be set, the power

use of the product may have to be changed accordingly.

f

2. In the case of products of safety class I with movable power cord and connector, operation is
permitted only on sockets with an earthing contact and protective earth connection.

3. Intentionally breaking the protective earth connection either in the feed line or in the product itself is
not permitted. Doing so can result in the danger of an electric shock from the product. If extension
cords or connector strips are implemented, they must be checked on a regular basis to ensure that
they are safe to use.

4. If the product does not have a power switch for disconnection from the AC supply network, the plug of
the connecting cable is regarded as the disconnecting device. In such cases, always ensure that the
power plug is easily reachable and accessible at all times (corresponding to the length of connecting
cable, approx. 2 m). Functional or electronic switches are not suitable for providing disconnection from
the AC supply network. If products without power switches are integrated into racks or systems, a
disconnecting device must be provided at the system level.

5. Never use the product if the power cable is damaged. Check the power cable on a regular basis to
ensure that it is in proper operating condition. By taking appropriate safety measures and carefully
laying the power cable, you can ensure that the cable will not be damaged and that no one can be
hurt by, for example, tripping over the cable or suffering an electric shock.

6. The product may be operated only from TN/TT supply networks fused with max. 16 A (higher fuse
only after consulting with the Rohde & Schwarz group of companies).

7. Do not insert the plug into sockets that are dusty or dirty. Insert the plug firmly and all the way into the
socket. Otherwise, sparks that result in fire and/or injuries may occur.

8. Do not overload any sockets, extension cords or connector strips; doing so can cause fire or electric
shocks.

9. For measurements in circuits with voltages V

> 30 V, suitable measures (e.g. appropriate

rms

measuring equipment, fusing, current limiting, electrical separation, insulation) should be taken to
avoid any hazards.

10. Ensure that the connections with information technology equipment, e.g. PCs or other industrial
computers, comply with the IEC60950-1/EN60950-1 or IEC61010-1/EN 61010-1 standards that apply
in each case.

11. Unless expressly permitted, never remove the cover or any part of the housing while the product is in
operation. Doing so will expose circuits and components and can lead to injuries, fire or damage to the
product.

12. If a product is to be permanently installed, the connection between the PE terminal on site and the
product's PE conductor must be made first before any other connection is made. The product may be
installed and connected only by a licensed electrician.

13. For permanently installed equipment without built-in fuses, circuit breakers or similar protective
devices, the supply circuit must be fused in such a way that anyone who has access to the product, as
well as the product itself, is adequately protected from injury or damage.

1171.0000.42-05.00 Page 3

Basic Safety Instructions

14. Use suitable overvoltage protection to ensure that no overvoltage (such as that caused by a bolt of
lightning) can reach the product. Otherwise, the person operating the product will be exposed to the
danger of an electric shock.

15. Any object that is not designed to be placed in the openings of the housing must not be used for this
purpose. Doing so can cause short circuits inside the product and/or electric shocks, fire or injuries.

6. Unless specified otherwise, products are not liquid-proof (see also section "Operating states and

1

operating positions", item 1. Therefore, the equipment must be protected against penetration by
liquids. If the necessary precautions are not taken, the user may suffer electric shock or the product
itself may be damaged, which can also lead to personal injury.

17. Never use the product under conditions in which condensation has formed or can form in or on the
product, e.g. if the product has been moved from a cold to a warm environment. Penetration by water
increases the risk of electric shock.

18. Prior to cleaning the product, disconnect it completely from the power supply (e.g. AC supply network
or battery). Use a soft, non-linting cloth to clean the product. Never use chemical cleaning agents such
as alcohol, acetone or diluents for cellulose lacquers.

Operation

1. Operating the products requires special training and intense concentration. Make sure that persons
who use the products are physically, mentally and emotionally fit enough to do so; otherwise, injuries
or material damage may occur. It is the responsibility of the employer/operator to select suitable
personnel for operating the products.

2. Before you move or transport the product, read and observe the section titled "Transport".

3. As with all industrially manufactured goods, the use of substances that induce an allergic reaction
(allergens) such as nickel cannot be generally excluded. If you develop an allergic reaction (such as a
skin rash, frequent sneezing, red eyes or respiratory difficulties) when using a Rohde & Schwarz
product, consult a physician immediately to determine the cause and to prevent health problems or
stress.

4. Before you start processing the product mechanically and/or thermally, or before you take it apart, be
sure to read and pay special attention to the section titled "Waste disposal", item 1.

5. Depending on the function, certain products such as RF radio equipment can produce an elevated
level of electromagnetic radiation. Considering that unborn babies require increased protection,
pregnant women must be protected by appropriate measures. Persons with pacemakers may also be
exposed to risks from electromagnetic radiation. The employer/operator must evaluate workplaces
where there is a special risk of exposure to radiation and, if necessary, take measures to avert the
potential danger.

6. Should a fire occur, the product may release hazardous substances (gases, fluids, etc.) that can
cause health problems. Therefore, suitable measures must be taken, e.g. protective masks and
protective clothing must be worn.

7. If a laser product (e.g. a CD/DVD drive) is integrated into a Rohde & Schwarz product, absolutely no
other settings or functions may be used as described in the product documentation. The objective is to
prevent personal injury (e.g. due to laser beams).

1171.0000.42-05.00 Page 4

Basic Safety Instructions

Repair and service

1. The product may be opened only by authorized, specially trained personnel. Before any work is
performed on the product or before the product is opened, it must be disconnected from the AC supply
network. Otherwise, personnel will be exposed to the risk of an electric shock.

2. Adjustments, replacement of parts, maintenance and repair may be performed only by electrical

xperts authorized by Rohde & Schwarz. Only original parts may be used for replacing parts relevant

e
to safety (e.g. power switches, power transformers, fuses). A safety test must always be performed
after parts relevant to safety have been replaced (visual inspection, PE conductor test, insulation
resistance measurement, leakage current measurement, functional test). This helps ensure the
continued safety of the product.

Batteries and rechargeable batteries/cells

If the information regarding batteries and rechargeable batteries/cells is not observed either at all or to the
extent necessary, product users may be exposed to the risk of explosions, fire and/or serious personal
injury, and, in some cases, death. Batteries and rechargeable batteries with alkaline electrolytes (e.g.
lithium cells) must be handled in accordance with the EN 62133 standard.

1. Cells must not be taken apart or crushed.

2. Cells or batteries must not be exposed to heat or fire. Storage in direct sunlight must be avoided.
Keep cells and batteries clean and dry. Clean soiled connectors using a dry, clean cloth.

3. Cells or batteries must not be short-circuited. Cells or batteries must not be stored in a box or in a
drawer where they can short-circuit each other, or where they can be short-circuited by other
conductive materials. Cells and batteries must not be removed from their original packaging until they
are ready to be used.

4. Keep cells and batteries out of the hands of children. If a cell or a battery has been swallowed, seek
medical aid immediately.

5. Cells and batteries must not be exposed to any mechanical shocks that are stronger than permitted.

6. If a cell develops a leak, the fluid must not be allowed to come into contact with the skin or eyes. If
contact occurs, wash the affected area with plenty of water and seek medical aid.

7. Improperly replacing or charging cells or batteries that contain alkaline electrolytes (e.g. lithium cells)
can cause explosions. Replace cells or batteries only with the matching Rohde & Schwarz type (see
parts list) in order to ensure the safety of the product.

8. Cells and batteries must be recycled and kept separate from residual waste. Rechargeable batteries
and normal batteries that contain lead, mercury or cadmium are hazardous waste. Observe the
national regulations regarding waste disposal and recycling.

Transport

1. The product may be very heavy. Therefore, the product must be handled with care. In some cases,
the user may require a suitable means of lifting or moving the product (e.g. with a lift-truck) to avoid
back or other physical injuries.

1171.0000.42-05.00 Page 5

Informaciones elementales de seguridad

2. Handles on the products are designed exclusively to enable personnel to transport the product. It is
therefore not permissible to use handles to fasten the product to or on transport equipment such as
cranes, fork lifts, wagons, etc. The user is responsible for securely fastening the products to or on the
means of transport or lifting. Observe the safety regulations of the manufacturer of the means of
transport or lifting. Noncompliance can result in personal injury or material damage.

3. If you use the product in a vehicle, it is the sole responsibility of the driver to drive the vehicle safely
and properly. The manufacturer assumes no responsibility for accidents or collisions. Never use the
product in a moving vehicle if doing so could distract the driver of the vehicle. Adequately secure the
product in the vehicle to prevent injuries or other damage in the event of an accident.

Waste disposal

1. If products or their components are mechanically and/or thermally processed in a manner that goes
beyond their intended use, hazardous substances (heavy-metal dust such as lead, beryllium, nickel)
may be released. For this reason, the product may only be disassembled by specially trained
personnel. Improper disassembly may be hazardous to your health. National waste disposal
regulations must be observed.

2. If handling the product releases hazardous substances or fuels that must be disposed of in a special
way, e.g. coolants or engine oils that must be replenished regularly, the safety instructions of the
manufacturer of the hazardous substances or fuels and the applicable regional waste disposal
regulations must be observed. Also observe the relevant safety instructions in the product
documentation. The improper disposal of hazardous substances or fuels can cause health problems
and lead to environmental damage.

Informaciones elementales de seguridad

Es imprescindible leer y observar las siguientes instrucciones e informaciones de seguridad!

El principio del grupo de empresas Rohde & Schwarz consiste en tener nuestros productos siempre al día
con los estándares de seguridad y de ofrecer a nuestros clientes el máximo grado de seguridad. Nuestros
productos y todos los equipos adicionales son siempre fabricados y examinados según las normas de
seguridad vigentes. Nuestro sistema de garantía de calidad controla constantemente que sean cumplidas
estas normas. El presente producto ha sido fabricado y examinado según el certificado de conformidad
adjunto de la UE y ha salido de nuestra planta en estado impecable según los estándares técnicos de
seguridad. Para poder preservar este estado y garantizar un funcionamiento libre de peligros, el usuario
deberá atenerse a todas las indicaciones, informaciones de seguridad y notas de alerta. El grupo de
empresas Rohde & Schwarz está siempre a su disposición en caso de que tengan preguntas referentes a
estas informaciones de seguridad.

Además queda en la responsabilidad del usuario utilizar el producto en la forma debida. Este producto
está destinado exclusivamente al uso en la industria y el laboratorio o, si ha sido expresamente
autorizado, para aplicaciones de campo y de ninguna manera deberá ser utilizado de modo que alguna
persona/cosa pueda sufrir daño. El uso del producto fuera de sus fines definidos o sin tener en cuenta las
instrucciones del fabricante queda en la responsabilidad del usuario. El fabricante no se hace en ninguna
forma responsable de consecuencias a causa del mal uso del producto.

1171.0000.42-05.00 Page 6

Informaciones elementales de seguridad

Se parte del uso correcto del producto para los fines definidos si el producto es utilizado conforme a las
indicaciones de la correspondiente documentación del producto y dentro del margen de rendimiento
definido (ver hoja de datos, documentación, informaciones de seguridad que siguen). El uso del producto
hace necesarios conocimientos técnicos y ciertos conocimientos del idioma inglés. Por eso se debe tener
en cuenta que el producto solo pueda ser operado por personal especializado o personas instruidas en
profundidad con las capacidades correspondientes. Si fuera necesaria indumentaria de seguridad para el

so de productos de Rohde & Schwarz, encontraría la información debida en la documentación del

u
producto en el capítulo correspondiente. Guarde bien las informaciones de seguridad elementales, así
como la documentación del producto, y entréguelas a usuarios posteriores.

Tener en cuenta las informaciones de seguridad sirve para evitar en lo posible lesiones o daños por
peligros de toda clase. Por eso es imprescindible leer detalladamente y comprender por completo las
siguientes informaciones de seguridad antes de usar el producto, y respetarlas durante el uso del
producto. Deberán tenerse en cuenta todas las demás informaciones de seguridad, como p. ej. las
referentes a la protección de personas, que encontrarán en el capítulo correspondiente de la
documentación del producto y que también son de obligado cumplimiento. En las presentes
informaciones de seguridad se recogen todos los objetos que distribuye el grupo de empresas
Rohde & Schwarz bajo la denominación de "producto", entre ellos también aparatos, instalaciones así
como toda clase de accesorios.

Símbolos y definiciones de seguridad

Aviso: punto de
peligro general

Observar la
documentación
del producto

Tensión de
alimentación de
PUESTA EN
MARCHA /
PARADA

Atención en
el manejo de
dispositivos
de peso
elevado

Indicación de
estado de
espera
(Standby)

Peligro de
choque
eléctrico

Corriente
continua (DC)

Adver­tencia:
superficie
caliente

Conexión a
conductor de
protección

Corriente alterna
(AC)

Conexión
a tierra

Corriente
continua /
Corriente alterna
(DC/AC)

Conexión
a masa

El aparato está protegido
en su totalidad por un
aislamiento doble
(reforzado)

Aviso: Cuidado
en el manejo de
dispositivos
sensibles a la
electrostática
(ESD)

1171.0000.42-05.00 Page 7

Informaciones elementales de seguridad

Palabras de señal y su significado

En la documentación del producto se utilizan las siguientes palabras de señal con el fin de advertir contra
riesgos y peligros.

PELIGRO identifica un peligro inminente con riesgo elevado que
provocará muerte o lesiones graves si no se evita.

ADVERTENCIA identifica un posible peligro con riesgo medio de
provocar muerte o lesiones (graves) si no se evita.

ATENCIÓN identifica un peligro con riesgo reducido de provocar
lesiones leves o moderadas si no se evita.

AVISO indica la posibilidad de utilizar mal el producto y, como
consecuencia, dañarlo.
En la documentación del producto se emplea de forma sinónima el
término CUIDADO.

Las palabras de señal corresponden a la definición habitual para aplicaciones civiles en el área
económica europea. Pueden existir definiciones diferentes a esta definición en otras áreas económicas o
en aplicaciones militares. Por eso se deberá tener en cuenta que las palabras de señal aquí descritas
sean utilizadas siempre solamente en combinación con la correspondiente documentación del producto y
solamente en combinación con el producto correspondiente. La utilización de las palabras de señal en
combinación con productos o documentaciones que no les correspondan puede llevar a interpretaciones
equivocadas y tener por consecuencia daños en personas u objetos.

Estados operativos y posiciones de funcionamiento

El producto solamente debe ser utilizado según lo indicado por el fabricante respecto a los estados
operativos y posiciones de funcionamiento sin que se obstruya la ventilación. Si no se siguen las
indicaciones del fabricante, pueden producirse choques eléctricos, incendios y/o lesiones graves con
posible consecuencia de muerte. En todos los trabajos deberán ser tenidas en cuenta las normas
nacionales y locales de seguridad del trabajo y de prevención de accidentes.

1. Si no se convino de otra manera, es para los productos Rohde & Schwarz válido lo que sigue:
como posición de funcionamiento se define por principio la posición con el suelo de la caja para
abajo, modo de protección IP 2X, grado de suciedad 2, categoría de sobrecarga eléctrica 2, uso
solamente en estancias interiores, utilización hasta 2000 m sobre el nivel del mar, transporte hasta
4500 m sobre el nivel del mar. Se aplicará una tolerancia de ±10 % sobre el voltaje nominal y de
±5 % sobre la frecuencia nominal.

2. No sitúe el producto encima de superficies, vehículos, estantes o mesas, que por sus características
de peso o de estabilidad no sean aptos para él. Siga siempre las instrucciones de instalación del
fabricante cuando instale y asegure el producto en objetos o estructuras (p. ej. paredes y estantes). Si
se realiza la instalación de modo distinto al indicado en la documentación del producto, pueden
causarse lesiones o incluso la muerte.

3. No ponga el producto sobre aparatos que generen calor (p. ej. radiadores o calefactores). La
temperatura ambiente no debe superar la temperatura máxima especificada en la documentación del
producto o en la hoja de datos. En caso de sobrecalentamiento del producto, pueden producirse
choques eléctricos, incendios y/o lesiones graves con posible consecuencia de muerte.

1171.0000.42-05.00 Page 8

Informaciones elementales de seguridad

Seguridad eléctrica

Si no se siguen (o se siguen de modo insuficiente) las indicaciones del fabricante en cuanto a seguridad
eléctrica, pueden producirse choques eléctricos, incendios y/o lesiones graves con posible consecuencia
de muerte.

1. Antes de la puesta en marcha del producto se deberá comprobar siempre que la tensión

reseleccionada en el producto coincida con la de la red de alimentación eléctrica. Si es necesario

p
modificar el ajuste de tensión, también se deberán cambiar en caso dado los fusibles
correspondientes del producto.

2. Los productos de la clase de protección I con alimentación móvil y enchufe individual solamente
podrán enchufarse a tomas de corriente con contacto de seguridad y con conductor de protección
conectado.

3. Queda prohibida la interrupción intencionada del conductor de protección, tanto en la toma de
corriente como en el mismo producto. La interrupción puede tener como consecuencia el riesgo de
que el producto sea fuente de choques eléctricos. Si se utilizan cables alargadores o regletas de
enchufe, deberá garantizarse la realización de un examen regular de los mismos en cuanto a su
estado técnico de seguridad.

4. Si el producto no está equipado con un interruptor para desconectarlo de la red, se deberá considerar
el enchufe del cable de conexión como interruptor. En estos casos se deberá asegurar que el enchufe
siempre sea de fácil acceso (de acuerdo con la longitud del cable de conexión, aproximadamente
2 m). Los interruptores de función o electrónicos no son aptos para el corte de la red eléctrica. Si los
productos sin interruptor están integrados en bastidores o instalaciones, se deberá colocar el
interruptor en el nivel de la instalación.

5. No utilice nunca el producto si está dañado el cable de conexión a red. Compruebe regularmente el
correcto estado de los cables de conexión a red. Asegúrese, mediante las medidas de protección y
de instalación adecuadas, de que el cable de conexión a red no pueda ser dañado o de que nadie
pueda ser dañado por él, p. ej. al tropezar o por un choque eléctrico.

6. Solamente está permitido el funcionamiento en redes de alimentación TN/TT aseguradas con fusibles
de 16 A como máximo (utilización de fusibles de mayor amperaje solo previa consulta con el grupo de
empresas Rohde & Schwarz).

7. Nunca conecte el enchufe en tomas de corriente sucias o llenas de polvo. Introduzca el enchufe por
completo y fuertemente en la toma de corriente. La no observación de estas medidas puede provocar
chispas, fuego y/o lesiones.

8. No sobrecargue las tomas de corriente, los cables alargadores o las regletas de enchufe ya que esto
podría causar fuego o choques eléctricos.

9. En las mediciones en circuitos de corriente con una tensión U

> 30 V se deberán tomar las medidas

eff

apropiadas para impedir cualquier peligro (p. ej. medios de medición adecuados, seguros, limitación
de tensión, corte protector, aislamiento etc.).

10. Para la conexión con dispositivos informáticos como un PC o un ordenador industrial, debe
comprobarse que éstos cumplan los estándares IEC60950-1/EN60950-1 o IEC61010-1/EN 61010-1
válidos en cada caso.

11. A menos que esté permitido expresamente, no retire nunca la tapa ni componentes de la carcasa
mientras el producto esté en servicio. Esto pone a descubierto los cables y componentes eléctricos y
puede causar lesiones, fuego o daños en el producto.

1171.0000.42-05.00 Page 9

Informaciones elementales de seguridad

12. Si un producto se instala en un lugar fijo, se deberá primero conectar el conductor de protección fijo
con el conductor de protección del producto antes de hacer cualquier otra conexión. La instalación y
la conexión deberán ser efectuadas por un electricista especializado.

13. En el caso de dispositivos fijos que no estén provistos de fusibles, interruptor automático ni otros
mecanismos de seguridad similares, el circuito de alimentación debe estar protegido de modo que
todas las personas que puedan acceder al producto, así como el producto mismo, estén a salvo de
posibles daños.

14. Todo producto debe estar protegido contra sobretensión (debida p. ej. a una caída del rayo) mediante
los correspondientes sistemas de protección. Si no, el personal que lo utilice quedará expuesto al
peligro de choque eléctrico.

15. No debe introducirse en los orificios de la caja del aparato ningún objeto que no esté destinado a ello.
Esto puede producir cortocircuitos en el producto y/o puede causar choques eléctricos, fuego o
lesiones.

16. Salvo indicación contraria, los productos no están impermeabilizados (ver también el capítulo
"Estados operativos y posiciones de funcionamiento", punto 1). Por eso es necesario tomar las
medidas necesarias para evitar la entrada de líquidos. En caso contrario, existe peligro de choque
eléctrico para el usuario o de daños en el producto, que también pueden redundar en peligro para las
personas.

17. No utilice el producto en condiciones en las que pueda producirse o ya se hayan producido
condensaciones sobre el producto o en el interior de éste, como p. ej. al desplazarlo de un lugar frío a
otro caliente. La entrada de agua aumenta el riesgo de choque eléctrico.

18. Antes de la limpieza, desconecte por completo el producto de la alimentación de tensión (p. ej. red de
alimentación o batería). Realice la limpieza de los aparatos con un paño suave, que no se deshilache.
No utilice bajo ningún concepto productos de limpieza químicos como alcohol, acetona o diluyentes
para lacas nitrocelulósicas.

Funcionamiento

1. El uso del producto requiere instrucciones especiales y una alta concentración durante el manejo.
Debe asegurarse que las personas que manejen el producto estén a la altura de los requerimientos
necesarios en cuanto a aptitudes físicas, psíquicas y emocionales, ya que de otra manera no se
pueden excluir lesiones o daños de objetos. El empresario u operador es responsable de seleccionar
el personal usuario apto para el manejo del producto.

2. Antes de desplazar o transportar el producto, lea y tenga en cuenta el capítulo "Transporte".

3. Como con todo producto de fabricación industrial no puede quedar excluida en general la posibilidad
de que se produzcan alergias provocadas por algunos materiales empleados, los llamados alérgenos
(p. ej. el níquel). Si durante el manejo de productos Rohde & Schwarz se producen reacciones
alérgicas, como p. ej. irritaciones cutáneas, estornudos continuos, enrojecimiento de la conjuntiva o
dificultades respiratorias, debe avisarse inmediatamente a un médico para investigar las causas y
evitar cualquier molestia o daño a la salud.

4. Antes de la manipulación mecánica y/o térmica o el desmontaje del producto, debe tenerse en cuenta
imprescindiblemente el capítulo "Eliminación", punto 1.

1171.0000.42-05.00 Page 10

Informaciones elementales de seguridad

5. Ciertos productos, como p. ej. las instalaciones de radiocomunicación RF, pueden a causa de su
función natural, emitir una radiación electromagnética aumentada. Deben tomarse todas las medidas
necesarias para la protección de las mujeres embarazadas. También las personas con marcapasos
pueden correr peligro a causa de la radiación electromagnética. El empresario/operador tiene la
obligación de evaluar y señalizar las áreas de trabajo en las que exista un riesgo elevado de
exposición a radiaciones.

6. Tenga en cuenta que en caso de incendio pueden desprenderse del producto sustancias tóxicas
(gases, líquidos etc.) que pueden generar daños a la salud. Por eso, en caso de incendio deben
usarse medidas adecuadas, como p. ej. máscaras antigás e indumentaria de protección.

7. En caso de que un producto Rohde & Schwarz contenga un producto láser (p. ej. un lector de
CD/DVD), no debe usarse ninguna otra configuración o función aparte de las descritas en la
documentación del producto, a fin de evitar lesiones (p. ej. debidas a irradiación láser).

Reparación y mantenimiento

1. El producto solamente debe ser abierto por personal especializado con autorización para ello. Antes
de manipular el producto o abrirlo, es obligatorio desconectarlo de la tensión de alimentación, para
evitar toda posibilidad de choque eléctrico.

2. El ajuste, el cambio de partes, el mantenimiento y la reparación deberán ser efectuadas solamente
por electricistas autorizados por Rohde & Schwarz. Si se reponen partes con importancia para los
aspectos de seguridad (p. ej. el enchufe, los transformadores o los fusibles), solamente podrán ser
sustituidos por partes originales. Después de cada cambio de partes relevantes para la seguridad
deberá realizarse un control de seguridad (control a primera vista, control del conductor de
protección, medición de resistencia de aislamiento, medición de la corriente de fuga, control de
funcionamiento). Con esto queda garantizada la seguridad del producto.

Baterías y acumuladores o celdas

Si no se siguen (o se siguen de modo insuficiente) las indicaciones en cuanto a las baterías y
acumuladores o celdas, pueden producirse explosiones, incendios y/o lesiones graves con posible
consecuencia de muerte. El manejo de baterías y acumuladores con electrolitos alcalinos (p. ej. celdas de
litio) debe seguir el estándar EN 62133.

1. No deben desmontarse, abrirse ni triturarse las celdas.

2. Las celdas o baterías no deben someterse a calor ni fuego. Debe evitarse el almacenamiento a la luz
directa del sol. Las celdas y baterías deben mantenerse limpias y secas. Limpiar las conexiones
sucias con un paño seco y limpio.

3. Las celdas o baterías no deben cortocircuitarse. Es peligroso almacenar las celdas o baterías en
estuches o cajones en cuyo interior puedan cortocircuitarse por contacto recíproco o por contacto con
otros materiales conductores. No deben extraerse las celdas o baterías de sus embalajes originales
hasta el momento en que vayan a utilizarse.

4. Mantener baterías y celdas fuera del alcance de los niños. En caso de ingestión de una celda o
batería, avisar inmediatamente a un médico.

5. Las celdas o baterías no deben someterse a impactos mecánicos fuertes indebidos.

1171.0000.42-05.00 Page 11

Informaciones elementales de seguridad

6. En caso de falta de estanqueidad de una celda, el líquido vertido no debe entrar en contacto con la
piel ni los ojos. Si se produce contacto, lavar con agua abundante la zona afectada y avisar a un
médico.

7. En caso de cambio o recarga inadecuados, las celdas o baterías que contienen electrolitos alcalinos
(p. ej. las celdas de litio) pueden explotar. Para garantizar la seguridad del producto, las celdas o
baterías solo deben ser sustituidas por el tipo Rohde & Schwarz correspondiente (ver lista de
recambios).

8. Las baterías y celdas deben reciclarse y no deben tirarse a la basura doméstica. Las baterías o
acumuladores que contienen plomo, mercurio o cadmio deben tratarse como residuos especiales.
Respete en esta relación las normas nacionales de eliminación y reciclaje.

Transporte

1. El producto puede tener un peso elevado. Por eso es necesario desplazarlo o transportarlo con
precaución y, si es necesario, usando un sistema de elevación adecuado (p. ej. una carretilla
elevadora), a fin de evitar lesiones en la espalda u otros daños personales.

2. Las asas instaladas en los productos sirven solamente de ayuda para el transporte del producto por
personas. Por eso no está permitido utilizar las asas para la sujeción en o sobre medios de transporte
como p. ej. grúas, carretillas elevadoras de horquilla, carros etc. Es responsabilidad suya fijar los
productos de manera segura a los medios de transporte o elevación. Para evitar daños personales o
daños en el producto, siga las instrucciones de seguridad del fabricante del medio de transporte o
elevación utilizado.

3. Si se utiliza el producto dentro de un vehículo, recae de manera exclusiva en el conductor la
responsabilidad de conducir el vehículo de manera segura y adecuada. El fabricante no asumirá
ninguna responsabilidad por accidentes o colisiones. No utilice nunca el producto dentro de un
vehículo en movimiento si esto pudiera distraer al conductor. Asegure el producto dentro del vehículo
debidamente para evitar, en caso de un accidente, lesiones u otra clase de daños.

Eliminación

1. Si se trabaja de manera mecánica y/o térmica cualquier producto o componente más allá del
funcionamiento previsto, pueden liberarse sustancias peligrosas (polvos con contenido de metales
pesados como p. ej. plomo, berilio o níquel). Por eso el producto solo debe ser desmontado por
personal especializado con formación adecuada. Un desmontaje inadecuado puede ocasionar daños
para la salud. Se deben tener en cuenta las directivas nacionales referentes a la eliminación de
residuos.

2. En caso de que durante el trato del producto se formen sustancias peligrosas o combustibles que
deban tratarse como residuos especiales (p. ej. refrigerantes o aceites de motor con intervalos de
cambio definidos), deben tenerse en cuenta las indicaciones de seguridad del fabricante de dichas
sustancias y las normas regionales de eliminación de residuos. Tenga en cuenta también en caso
necesario las indicaciones de seguridad especiales contenidas en la documentación del producto. La
eliminación incorrecta de sustancias peligrosas o combustibles puede causar daños a la salud o
daños al medio ambiente.

1171.0000.42-05.00 Page 12

Sicherheitshinweise

disposed of at a

Después de la vida útil, la batería sólo se podrá eliminar en

Kundeninformation zur Batterieverordnung (BattV)

Dieses Gerät enthält eine schadstoffhaltige Batterie. Diese
darf nicht mit dem Hausmüll entsorgt werden.

Nach Ende der Lebensdauer darf die Entsorgung nur über
eine Rohde&Schwarz-Kundendienststelle oder eine geeig­nete Sammelstelle erfolgen.

Safety Regulations for Batteries
(according to BattV)

This equipment houses a battery containing harmful sub­stances that must not be disposed of as normal household
waste.

After its useful life, the battery may only be
Rohde & Schwarz service center or at a suitable depot.

Normas de Seguridad para Baterías
(Según BattV)

Este equipo lleva una batería que contiene sustancias per­judiciales, que no se debe desechar en los contenedores
de basura domésticos.

un centro de servicio de Rohde & Schwarz o en un
depósito apropiado.

Consignes de sécurité pour batteries
(selon BattV)

Cet appareil est équipé d'une pile comprenant des sub­stances nocives. Ne jamais la jeter dans une poubelle pour
ordures ménagéres.

Une pile usagée doit uniquement être éliminée par un cen­tre de service client de Rohde & Schwarz ou peut être col­lectée pour être traitée spécialement comme déchets dan­gereux.

1171.0300.41 D/E/ESP/F-2

Customer Information Regarding Product Disposal

The German Electrical and Electronic Equipment (ElektroG) Act is an implementation of
the following EC directives:

2002/96/EC on waste electrical and electronic equipment (WEEE) and

•

•

2002/95/EC on the restriction of the use of certain hazardous substances in
e

lectrical and electronic equipment (RoHS).

Product labeling in accordance with EN 50419

Once the lifetime of a product has ended, this product must not be disposed of
in the standard domestic refuse. Even disposal via the municipal collection
points for waste electrical and electronic equipment is not permitted.

Rohde & Schwarz GmbH & Co. KG has developed a disposal concept for the
environmental-friendly

as

obligation
in accordance with the ElektroG Act.

Please contact your local service representative to dispose of the product.

a producer to take back and dispose of electrical and electronic waste

disposal or recycling of waste material and fully assumes its

1171.0200.52-01.01

Qualitätszertikat

Certied Quality System

ISO 9001

Certicate of quality
Certicat de qualité

Sehr geehrter Kunde,

Sie haben sich für den Kauf eines
Rohde & Schwarz-Produktes ent­schieden. Hiermit erhalten Sie ein
nach modernsten Fertigungsmethoden
hergestelltes Produkt. Es wurde nach
den Regeln unseres Qualitätsmanage­mentsystems entwickelt, gefertigt
und geprüft. Das Rohde & Schwarz­Qualitätsmanagementsystem ist u.a.
nach ISO 9001 und ISO 14001

zertiziert.

Der Umwelt verpflichtet

J

Energie-efziente,
RoHS-konforme Produkte

J

Kontinuierliche Weiterentwicklung
nachhaltiger Umweltkonzepte

J

ISO 14001-zertiziertes
Umweltmanagementsystem

Dear Customer,

You have decided to buy a
Rohde & Schwarz product. You are
thus assured of receiving a product
that is manufactured using the most
modern methods available. This
product was developed, manufactured
and tested in compliance with our
quality management system stan­dards. The Rohde & Schwarz quality

management system is certied

according to standards such as
ISO 9001 and ISO 14001.

Environmental commitment

J

Energy-efcient products

Continuous improvement in J
environmental sustainability

J

ISO 14001-certied environmental

management system

Certied Environmental System

ISO 14001

Cher client,

Vous avez choisi d’acheter un pro­duit Rohde & Schwarz. Vous disposez
donc d’un produit fabriqué d’après les
méthodes les plus avancées. Le déve­loppement, la fabrication et les tests
respectent nos normes de gestion
qualité. Le système de gestion qualité
de Rohde & Schwarz a été homologué,
entre autres, conformément aux nor­mes ISO 9001 et ISO 14001.

Engagement écologique

J

Produits à efcience énergétique

Amélioration continue de la durabilité J
environnementale

J

Système de gestion de l’environne-

ment certié selon ISO 14001

1171.0200.11 V 04.01

Customer Support

Technical support – where and when you need it

For quick, expert help with any Rohde & Schwarz equipment, contact one of our Customer Support
Centers. A team of highly qualified engineers provides telephone support and will work with you to find a
solution to your query on any aspect of the operation, programming or applications of Rohde & Schwarz
equipment.

Up-to-date information and upgrades

To keep your instrument up-to-date and to be informed about new application notes related to your
instrument, please send an e-mail to the Customer Support Center stating your instrument and your wish.
We will take care that you will get the right information.

USA & Canada

East Asia

Rest of the World

Monday to Friday (except US public holidays)
8:00 AM – 8:00 PM Eastern Standard Time (EST)

Tel. from USA 888-test-rsa (888-837-8772) (opt 2)
From outside USA [phone] (opt 2)
Fax [phone]

E-mail [e-mail]

Monday to Friday (except Singaporean public holidays)
8:30 AM – 6:00 PM Singapore Time (SGT)

Tel. [phone]
Fax [phone]

E-mail [e-mail]

Monday to Friday (except German public holidays)
08:00 – 17:00 Central European Time (CET)

Tel. [phone]
Fax [phone]

E-mail [e-mail]

1171.0200.22-04.00

R&S FSP Documentation Overview

Tabbed Divider Overview

Safety Instructions are provided on the CD-ROM

Tabbed Divider

Documentation Overview

Chapter 1: Putting into Operation

Chapter 2: Getting Started

Chapter 3: Manual Operation

Chapter 4: Instrument Functions

Chapter 5: Remote Control – Basics

Chapter 6: Remote Control – Description of Commands

Chapter 7: Remote Control – Programming Examples

Chapter 8: Maintenance and Instrument Interfaces

Chapter 9: Error Messages

Index

Operating Manual 1164.4556.12 - 06 4.1

R&S FSP Documentation Overview

Documentation Overview

The documentation of the R&S FSP consists of base unit manuals and option man­uals. All manuals are provided in PDF format on the CD-ROM delivered with the
instrument. Each software option available for the instrument is described in a sepa­rate software manual.

The base unit documentation comprises the following manuals and documents:

• Quick Start Guide

• Operating Manual

• Service Manual

• Internet Site

• Release Notes

Apart from the base unit, these manuals describe the following models and options
of the R&S FSP Spectrum Analyzer. Options that are not listed are described in sep­arate manuals. These manuals are provided on an extra CD-ROM. For an overview
of all options available for the R&S FSP visit the R&S FSP Spectrum Analyzer Inter­net site.

Base unit models:

• R&S FSP3 (9 kHz to 3 GHz)

• R&S FSP7 (9 kHz to 7 GHz)

• R&S FSP13 (9 kHz to 13.6 GHz)

• R&S FSP30 (9 kHz to 30 GHz)

• R&S FSP31 (9 kHz to 31 GHz)

• R&S FSP40 (9 kHz to 40 GHz)

Options described in the base unit manuals:

• R&S FSP-B3 (Audio Demodulator)

• R&S FSP-B4 (OCXO - reference oscillator)

• R&S FSP-B6 (TV and RF Trigger)

• R&S FSP-B9 (Tracking Generator)

• R&S FSP-B10 (External Generator Control)

• R&S FSP-B15 (Broadband Calibration Source)

• R&S FSP-B16 (LAN Interface)

• R&S FSP-B18 (removable Hard Disk)

• R&S FSP-B19 (second Hard Disk for R&S FSP-B18 option)

• R&S FSP-B20 (Extended Environmental Specification)

• R&S FSP-B21 (External Mixer)

• R&S FSP-B25 (Electronic Attenuator)

• R&S FSP-B28 (Trigger Port)

• R&S FSP-B29 (20 Hz Frequency Extension)

• R&S FSP-B70 (FSP Demodulator for WCDMA BTS measurements)

4.2 Operating Manual 1164.4556.12 - 06

R&S FSP Documentation Overview

Quick Start Guide

This manual is delivered with the instrument in printed form and in PDF format on
the CD-ROM. It provides the information needed to set up and start working with the
instrument. Basic operations and basic measurements are described. Also a brief
introduction to remote control is given. More detailed descriptions are provided in
the Operating Manual. The Quick Start Guide includes general information (e.g.
Safety Instructions) and the following chapters:

Chapter 1 Front and Rear Panel

Chapter 2 Preparing for Use

Chapter 3 Firmware-Update and Installation of Firmware Options

Chapter 4 Basic Operation

Chapter 5 Basic Measurement Examples

Chapter 6 LAN Interface

Appendix A Printer Interface

Appendix B External Generator Control

Appendix C Brief Introduction to Remote Control

Operating Manual

This manual is a supplement to the Quick Start Guide and is available in PDF format
on the CD-ROM delivered with the instrument. To retain the familiar structure that
applies to all operating manuals of Rohde&Schwarz Test & Measurement instru­ments, the chapters 1 and 3 exist, but only in form of references to the correspond­ing Quick Start Guide chapters. The operating manual has the following chapters:

Chapter 1 Putting into Operation

see Quick Start Guide chapters 1 and 2.

Chapter 2 Getting Started

see Quick Start Guide chapter 5.

Chapter 3 Manual Operation

see Quick Start Guide chapter 4.

Chapter 4 Instrument Functions

forms a reference for manual operation of the R&S FSP and con­tains a description of all instrument functions and their application.

Chapter 5 Remote Control - Basics

describes the basics for programming the R&S FSP, command pro­cessing and the status reporting system.

Chapter 6 Remote Control - Description of Commands

lists all the remote-control commands defined for the instrument.

Chapter 7 Remote Control - Programming Examples

contains program examples for a number of typical applications of
the R&S FSP.

Chapter 8 Maintenance and Instrument Interfaces

describes preventive maintenance and the characteristics of the
instrument’s interfaces.

Chapter 9 Error Messages

gives a list of error messages that the R&S FSP may generate.

Index contains an index for the chapters 1 to 9 of the operating manual.

Operating Manual 1164.4556.12 - 06 4.3

R&S FSP Documentation Overview

Service Manual

This manual is available in PDF format on the CD-ROM delivered with the instru­ment. It informs on how to check compliance with rated specifications, on instrument
function, repair, troubleshooting and fault elimination. It contains all information
required for repairing the R&S FSP by the replacement of modules. The manual
includes the following chapters:

Chapter 1 Performance Test

Chapter 2 Adjustment

Chapter 3 Repair

Chapter 4 Software Update / Installing Options

Chapter 5 Documents

Internet Site

The Internet site at: R&S FSP Signal Source Analyzer provides the most up to date
information on the R&S FSP.

The current operating manual at a time is available as printable PDF file in the
download area. Also provided for download are firmware updates including the
associated release notes, instrument drivers, current data sheets and application
notes.

Release Notes

The release notes describe the installation of the firmware, new and modified func­tions, eliminated problems, and last minute changes to the documentation. The cor­responding firmware version is indicated on the title page of the release notes. The
current release notes are provided in the Internet.

4.4 Operating Manual 1164.4556.12 - 06

R&S FSP Putting into Operation

1 Putting into Operation

For details refer to the Quick Start Guide chapter 1, “Front and Rear Panel” and
chapter 2, “ Preparing for Use”.

Operating Manual 1164.4556.12 - 06 1.1

R&S FSP Putting into Operation

1.2 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

2 Getting Started

2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2

2.2 Measuring the Spectra of Complex Signals . . . . . . . . . . . . . . . . . . . . . . . . 2.2

2.2.1 Intermodulation Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2

2.2.2 Measurement Example – Measuring the R&S FSP’s intrinsic

intermodulation distance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4

2.3 Measuring Signals in the Vicinity of Noise . . . . . . . . . . . . . . . . . . . . . . . . . 2.8

2.3.0.1Measurement example – Measuring the level of the internal

reference generator at low S/N ratios . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.11

2.4 Noise Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.14

2.4.1 Measuring noise power density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.14

2.4.1.1Measurement example – Measuring the intrinsic noise power
density of the R&S FSP at 1 GHz and calculating the R&S FSP’s

noise figure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.14

2.4.2 Measurement of Noise Power within a Transmission Channel . . . . . . . 2.17

2.4.2.1Measurement Example – Measuring the intrinsic noise of the
R&S FSP at 1 GHz in a 1.23 MHz channel bandwidth with the

channel power function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.17

2.4.3 Measuring Phase Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.22

2.4.3.1Measurement Example – Measuring the phase noise of a

signal generator at a carrier offset of 10 kHz . . . . . . . . . . . . . . . . . . . . . . 2.22

2.5 Measurements on Modulated Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.23

2.5.1 Measurements on AM signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.23

2.5.1.1Measurement Example 1 – Displaying the AF of an AM signal in

the time domain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.24

2.5.1.2Measurement Example 2 – Measuring the modulation depth of

an AM carrier in the frequency domain . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.25

2.5.2 Measurements on FM Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.26

2.5.2.1Measurement Example – Displaying the AF of an FM carrier . . . . 2.27

2.5.3 Measuring Channel Power and Adjacent Channel Power . . . . . . . . . . 2.29

2.5.3.1Measurement Example 1 – ACPR measurement on an IS95

CDMA Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.30

2.5.3.2Measurement Example 2 – Measuring the adjacent channel

power of an IS136 TDMA signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.34

2.5.3.3Measurement Example 3 – Measuring the Modulation Spectrum

in Burst Mode with the Gated Sweep Function . . . . . . . . . . . . . . . . . . . . . 2.37

2.5.3.4Measurement Example 4 – Measuring the Transient Spectrum

in Burst Mode with the Fast ACP function . . . . . . . . . . . . . . . . . . . . . . . . . 2.39

2.5.3.5Measurement Example 5 – Measuring adjacent channel power

of a W-CDMA uplink signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.41

2.5.4 Amplitude distribution measurements . . . . . . . . . . . . . . . . . . . . . . . . . . 2.44

2.5.4.1Measurement Example – Measuring the APD and CCDF of

white noise generated by the R&S FSP . . . . . . . . . . . . . . . . . . . . . . . . . . 2.44

Operating Manual 1164.4556.12 - 06 2.1

R&S FSP Getting Started

Introduction

2.1 Introduction

This chapter explains how to operate the R&S FSP using typical measurements as
examples.

The basic operating steps such as selecting the menus and setting parameters are
described in the Quick Start Guide, chapter 4, "Basic Operation". Furthermore, the
screen structure and displayed function indicators are explained in this chapter.

Chapter “Instrument Functions” describes all the menus and R&S FSP functions.

All of the following examples are based on the standard settings of the R&S FSP.
These are set with the PRESET key. A complete listing of the standard settings can
be found in chapter “Instrument Functions”, section “R&S FSP Initial Configuration –

PRESET Key” on page 4.5. Examples of more basic character are provided in the

Quick Start Guide, chapter 5, as an introduction.

2.2 Measuring the Spectra of Complex Signals

2.2.1 Intermodulation Measurements

If several signals are applied to a DUT with non-linear characteristics, unwanted
mixing products are generated – mostly by active components such as amplifiers or
mixers. The products created by 3
some as they have frequencies close to the useful signals and, compared with other
products, are closest in level to the useful signals. The fundamental wave of one sig­nal is mixed with the 2

f

= 2 × fu1 – fu2 (6)

s1

= 2 × fu2 – fu1 (7)

f

s2

where f

and fs2 are the frequencies of the intermodulation products and fu1 and f

s1

nd

harmonic of the other signal.

the frequencies of the useful signals.

The following diagram shows the position of the intermodulation products in the fre­quency domain.

Level

P

u1

rd

order intermodulation are particularly trouble-

u2

P

u2

a

D3

P

s1

∆

∆

f

f

s1

Fig. 2.8 3rd order intermodulation products

f

u1

f

f

u2

P

s2

∆

f

f

s2

Frequency

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R&S FSP Getting Started

Measuring the Spectra of Complex Signals

Example:

fu1 = 100 MHz, fu2 = 100.03 MHz

= 2 × fu1 – fu2 = 2 × 100 MHz – 100.03 MHz = 99.97 MHz

f

s1

f

= 2 × fu2 – fu1 = 2 × 100.03 MHz – 100 MHz = 100.06 MHz

s2

The level of the intermodulation products depends on the level of the useful signals.
If the level of the two useful signals is increased by 1 dB, the level of the intermodu­lation products is increased by 3 dB. The intermodulation distance d

is, therefore,

3

reduced by 2 dB. Fig. 2.9 shows how the levels of the useful signals and the 3
order intermodulation products are related.

Output

level

Intercept

point

Compression

rd

Carrier

level

D3

a

1

1

Fig. 2.9 Level of the 3rd order intermodulation products as a function of the level of the useful

signals

1

Intermodulation

products

3

Input level

The behavior of the signals can be explained using an amplifier as an example. The
change in the level of the useful signals at the output of the amplifier is proportional
to the level change at the input of the amplifier as long as the amplifier is operating
in linear range. If the level at the amplifier input is changed by 1 dB, there is a 1 dB
level change at the amplifier output. At a certain input level, the amplifier enters sat­uration. The level at the amplifier output does not increase with increasing input
level.

The level of the 3
level of the useful signals. The 3

rd

order intermodulation products increases 3 times faster than the

rd

order intercept is the virtual level at which the
level of the useful signals and the level of the spurious products are identical, i.e. the
intersection of the two straight lines. This level cannot be measured directly as the
amplifier goes into saturation or is damaged before this level is reached.

rd

The 3
intermodulation distance d

order intercept can be calculated from the known slopes of the lines, the

and the level of the useful signals.

2

TOI = a

with TOI (Third Order Intercept) being the 3rd order intercept in dBm and P

/ 2 + Pn (10)

D3

the

n

level of a carrier in dBm.

Operating Manual 1164.4556.12 - 06 2.3

R&S FSP Getting Started

Measuring the Spectra of Complex Signals

With an intermodulation distance of 60 dB and an input level, Pw, of –20 dBm, the
following 3

rd

order intercept is obtained:

TOI = 60 dBm / 2 + (-20 dBm) = 10 dBm.

2.2.2 Measurement Example – Measuring the R&S FSP’s intrinsic
intermodulation distance

To measure the intrinsic intermodulation distance, use the following test setup.

Test setup:

Signal

Generator 1

Coupler R&S FSP

Signal

Generator 2

Settings on the signal generator (e.g. R&S SMIQ):

Level Frequency

Signal generator 1 -10 dBm 999.9 MHz

Signal generator 2 -10 dBm 1000.1 MHz

Measurement using the R&S FSP:

1. Set the R&S FSP to its default settings.

➢ Press the PRESET key.

The R&S FSP is in its default state.

2. Set center frequency to 1 GHz and the frequency span to 1 MHz.

➢ Press the FREQ key and enter 1 GHz.
➢ Press the SPAN key and enter 1 MHz.

3. Set the reference level to –10 dBm and RF attenuation to 0 dB.

➢ Press the AMPT key and enter -10 dBm.
➢ Press the RF ATTEN MANUAL softkey and enter 0 dB.

By reducing the RF attenuation to 0 dB, the level to the R&S FSP input mixer
is increased. Therefore, 3

rd

order intermodulation products are displayed.

4. Set the resolution bandwidth to 10 kHz.

➢ Press the BW key.

2.4 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Measuring the Spectra of Complex Signals

➢ Press the RES BW MANUAL softkey and enter 10 kHz.

By reducing the bandwidth, the noise is further reduced and the
intermodulation products can be clearly seen.

5. Measuring intermodulation by means of the 3

rd

order intercept

measurement function

➢ Press the MEAS key.
➢ Press the TOI softkey.

The R&S FSP activates four markers for measuring the intermodulation
distance. Two markers are positioned on the useful signals and two on the
intermodulation products. The 3

rd

order intercept is calculated from the level
difference between the useful signals and the intermodulation products. It is
then displayed on the screen:

Fig. 2-1 Result of intrinsic intermodulation measurement on the R&S FSP. The 3rd

order intercept (TOI) is displayed at the top right corner of the grid

The level of a Spectrum Analyzer’s intrinsic intermodulation products depends
on the RF level of the useful signals at the input mixer. When the RF
attenuation is added, the mixer level is reduced and the intermodulation
distance is increased. With an additional RF attenuation of 10 dB, the levels of
the intermodulation products are reduced by 20 dB. The noise level is,
however, increased by 10 dB.

6. Increasing RF attenuation to 10 dB to reduce intermodulation products.

➢ Press the AMPT key.
➢ Press the RF ATTEN MANUAL softkey and enter 10 dB.

The R&S FSP’s intrinsic intermodulation products disappear below the noise
floor.

Operating Manual 1164.4556.12 - 06 2.5

R&S FSP Getting Started

Measuring the Spectra of Complex Signals

Fig. 2-2 If the RF attenuation is increased, the R&S FSP’s intrinsic intermodulation

products disappear below the noise floor.

Calculation method:

The method used by the R&S FSP to calculate the intercept point takes the average
useful signal level P

in dBm and calculates the intermodulation d3 in dB as a func-

u

tion of the average value of the levels of the two intermodulation products. The third
order intercept (TOI) is then calculated as follows:

TOI/dBm = ½ d

+ Pu

3

Intermodulation- free dynamic range

The Intermodulation – free dynamic range, i.e. the level range in which no inter­nal intermodulation products are generated if two-tone signals are measured, is
determined by the 3

rd

order intercept point, the phase noise and the thermal noise of
the R&S FSP. At high signal levels, the range is determined by intermodulation
products. At low signal levels, intermodulation products disappear below the noise
floor, i.e. the noise floor and the phase noise of the R&S FSP determine the range.
The noise floor and the phase noise depend on the resolution bandwidth that has
been selected. At the smallest resolution bandwidth, the noise floor and phase noise
are at a minimum and so the maximum range is obtained. However, a large increase
in sweep time is required for small resolution bandwidths. It is, therefore, best to
select the largest resolution bandwidth possible to obtain the range that is required.
Since phase noise decreases as the carrier-offset increases, its influence decreases
with increasing frequency offset from the useful signals.

The following diagrams illustrate the intermodulation-free dynamic range as a func­tion of the selected bandwidth and of the level at the input mixer (= signal level – set
RF attenuation) at different useful signal offsets.

2.6 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

0

0

Measuring the Spectra of Complex Signals

Distortion free Dynamic Range

D

y

n

r

a

n

g

e

/

d

B

-40

-50

-60

-70

-80

-90

-100

-110

-120

-60 -50 -40 -30 -20 -1

RBW = 10

kHz

RBW = 1

kHz

RBW = 100

Hz

RBW = 10

Hz

(1 MHz carrier offset

)

T.O.I.

Thermal Noise

Mixer level /dBm

Fig. 2.11 Intermodulation-free range of the FSP3 as a function of level at the input mixer and the

set resolution bandwidth (useful signal offset = 1 MHz, DANL = -155 dBm /Hz, TOI = 12
dBm; typ. values at 2 GHz)

The optimum mixer level, i.e. the level at which the intermodulation distance is at its
maximum, depends on the bandwidth. At a resolution bandwidth of 10 Hz, it is
approx. –42 dBm and at 10 kHz increases to approx. -32 dBm.

Phase noise has a considerable influence on the intermodulation-free range at car­rier offsets between 10 and 100 kHz (Fig. 2.12). At greater bandwidths, the influence
of the phase noise is greater than it would be with small bandwidths. The optimum
mixer level at the bandwidths under consideration becomes almost independent of
bandwidth and is approx. –40 dBm.

Distortion free Dynamic Range

D

y

n

.

r

a

n

g

e

/

d

-40

-50

-60

-70

-80

-90

-100

B

RBW = 10

kHz

RBW = 1

kHz

RBW = 100

Hz

RBW = 10

Hz

(10 to 100 kHz carrier offset

)

-110

-120

-60 -50 -40 -30 -20 -1

Mixer level /dBm

Fig. 2.12 Intermodulation-free dynamic range of the FSP3 as a function of level at the input mixer

and of the selected resolution bandwidth (useful signal offset = 10 to 100 kHz, DANL = ­155 dBm /Hz, TOI = 12 dBm; typ. values at 2 GHz).

Operating Manual 1164.4556.12 - 06 2.7

R&S FSP Getting Started

Measuring Signals in the Vicinity of Noise

If the intermodulation products of a DUT with a very high dynamic range are to be
measured and the resolution bandwidth to be used is therefore very small, it is
best to measure the levels of the useful signals and those of the intermodulation
products separately using a small span. The measurement time will be reduced–
in particular if the offset of the useful signals is large. To find signals reliably when
frequency span is small, it is best to synchronize the signal sources and the R&S
FSP.

2.3 Measuring Signals in the Vicinity of Noise

The minimum signal level a Spectrum Analyzer can measure is limited by its intrinsic
noise. Small signals can be swamped by noise and therefore cannot be measured.
For signals that are just above the intrinsic noise, the accuracy of the level measure­ment is influenced by the intrinsic noise of the R&S FSP.

The displayed noise level of a Spectrum Analyzer depends on its noise figure, the
selected RF attenuation, the selected reference level, the selected resolution and
video bandwidth and the detector. The effect of the different parameters is explained
in the following.

Impact of the RF attenuation setting

The sensitivity of a Spectrum Analyzer is directly influenced by the selected RF
attenuation. The highest sensitivity is obtained at a RF attenuation of 0 dB. The
R&S FSP’s RF attenuation can be set in 10 dB steps up to 70 dB (5 dB steps up to
75 dB with option Electronic Attenuator R&S FSP-B25). Each additional 10 dB step
reduces the R&S FSP’s sensitivity by 10 dB, i.e. the displayed noise is increased by
10 dB.

Impact of the reference level setting

If the reference level is changed, the R&S FSP changes the gain on the last IF so
that the voltage at the logarithmic amplifier and the A/D converter is always the
same for signal levels corresponding to the reference level. This ensures that the
dynamic range of the log amp or the A/D converter is fully utilized. Therefore, the
total gain of the signal path is low at high reference levels and the noise figure of the
IF amplifier makes a substantial contribution to the total noise figure of the
R&S FSP. The figure below shows the change in the displayed noise depending on
the set reference level at 10 kHz and 300 kHz resolution bandwidth. With digital
bandwidths (≤100 kHz) the noise increases sharply at high reference levels because
of the dynamic range of the A/D converter.

2.8 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

z

W

Measuring Signals in the Vicinity of Noise

14

12

10

8

6

RBW = 10 kHz

4

rel. noise level /dB

2

0

-2

-70 -60 -50 -40 -30 -20
Reference level /dBm

Fig. 2.13 Change in displayed noise as a function of the selected reference level at bandwidths of

10 kHz and 300 kHz (-30 dBm reference level)

RBW = 300 kH

Impact of the resolution bandwidth

The sensitivity of a Spectrum Analyzer also directly depends on the selected band­width. The highest sensitivity is obtained at the smallest bandwidth (for the
R&S FSP: 10 Hz, for FFT filtering: 1 Hz). If the bandwidth is increased, the reduction
in sensitivity is proportional to the change in bandwidth. The R&S FSP has band­width settings in 3 and 10 sequence. Increasing the bandwidth by a factor of 3
increases the displayed noise by approx. 5 dB (4.77 dB precisely). If the bandwidth
is increased by a factor of 10, the displayed noise increases by a factor of 10, i.e. 10
dB. Because of the way the resolution filters are designed, the sensitivity of Spec­trum Analyzers often depends on the selected resolution bandwidth. In data sheets,
the displayed average noise level is often indicated for the smallest available band­width (for the R&S FSP: 10 Hz). The extra sensitivity obtained if the bandwidth is
reduced may therefore deviate from the values indicated above. The following table
illustrates typical deviations from the noise figure for a resolution bandwidth of 10
kHz which is used as a reference value (= 0 dB).

Noise fi gure

offset /dB

3

digital RBW analog RB

2

1

0

-1
0,01 0,1 1 10 100 1000

Fig. 2.14 Change in R&S FSP noise figure at various bandwidths. The reference bandwidth is 10

kHz

RBW /kHz

Operating Manual 1164.4556.12 - 06 2.9

R&S FSP Getting Started

Measuring Signals in the Vicinity of Noise

Impact of the video bandwidth

The displayed noise of a Spectrum Analyzer is also influenced by the selected video
bandwidth. If the video bandwidth is considerably smaller than the resolution band­width, noise spikes are suppressed, i.e. the trace becomes much smoother. The
level of a sinewave signal is not influenced by the video bandwidth. A sinewave sig­nal can therefore be freed from noise by using a video bandwidth that is small com­pared with the resolution bandwidth, and thus be measured more accurately.

Impact of the detector

Noise is evaluated differently by the different detectors. The noise display is there­fore influenced by the choice of detector. Sinewave signals are weighted in the
same way by all detectors, i.e. the level display for a sinewave RF signal does not
depend on the selected detector, provided that the signal-to-noise ratio is high
enough. The measurement accuracy for signals in the vicinity of R&S FSP intrinsic
noise is also influenced by the detector which has been selected. The R&S FSP has
the following detectors:

Maximum peak detector

If the max. peak detector s selected, the largest noise display is obtained, since the
R&S FSP displays the highest value of the IF envelope in the frequency range
assigned to a pixel at each pixel in the trace. With longer sweep times, the trace
indicates higher noise levels since the probability of obtaining a high noise amplitude
increases with the dwell time on a pixel. For short sweep times, the display
approaches that of the sample detector since the dwell time on a pixel is only suffi­cient to obtain an instantaneous value.

Minimum peak detector

The min. peak detector indicates the minimum voltage of the IF envelope in the fre­quency range assigned to a pixel at each pixel in the trace. The noise is strongly
suppressed by the minimum peak detector since the lowest noise amplitude that
occurs is displayed for each test point. If the signal-to-noise ratio is low, the mini­mum of the noise overlaying the signal is displayed too low.

At longer sweep times, the trace shows smaller noise levels since the probability of
obtaining a low noise amplitude increases with the dwell time on a pixel. For short
sweep times, the display approaches that of the sample detector since the dwell
time on a pixel is only sufficient to obtain an instantaneous value.

Autopeak detector

The Autopeak detector displays the maximum and minimum peak value at the same
time. Both values are measured and their levels are displayed on the screen joint by
a vertical line.

Sample detector

The sample detector samples the logarithm of the IF envelope for each pixel of the
trace only once and displays the resulting value. If the frequency span of the
R&S FSP is considerably higher than the resolution bandwidth (span/RBW >500),
there is no guarantee that useful signals will be detected. They are lost due to
undersampling. This does not happen with noise because in this case it is not the
instantaneous amplitude that is relevant but only the probability distribution.

2.10 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Measuring Signals in the Vicinity of Noise

RMS detector

For each pixel of the trace, the RMS detector outputs the RMS value of the IF enve­lope for the frequency range assigned to each test point. It therefore measures
noise power. The display for small signals is, however, the sum of signal power and
noise power. For short sweep times, i.e. if only one uncorrelated sample value con­tributes to the RMS value measurement, the RMS detector is equivalent to the sam­ple detector. If the sweep time is longer, more and more uncorrelated RMS values
contribute to the RMS value measurement. The trace is, therefore, smoothed. The
level of sinewave signals is only displayed correctly if the selected resolution band­width (RBW) is at least as wide as the frequency range which corresponds to a pixel
in the trace. At a resolution bandwidth of 1 MHz, this means that the maximum fre­quency display range is 501 MHz.

Average detector

For each pixel of the trace, the average detector outputs the average value of the
linear IF envelope for the frequency range assigned to each test point. It therefore
measures the linear average noise. The level of sinewave signals is only displayed
correctly if the selected resolution bandwidth (RBW) is at least as wide as the fre­quency range which corresponds to a pixel in the trace. At a resolution bandwidth of
1 MHz, this means the maximum frequency display range is 501 MHz.

Quasi peak detector

The quasi peak detector is a peak detector for EMI measurements with defined
charge and discharge times. These times are defined in CISPR 16, the standard for
equipment used to measure EMI emissions.

2.3.0.1 Measurement example – Measuring the level of the internal reference genera­tor at low S/N ratios

The example shows the different factors influencing the S/N ratio.

1. Set the R&S FSP to its default state.

➢ Press the PRESET key.

The R&S FSP is in its default state.

2. Switch on the internal reference generator

➢ Press the SETUP key.
➢ Press the softkeys SERVICE - INPUT CAL.

The internal 128 MHz reference generator is on.
The R&S FSP’s RF input is off.

3. Set the center frequency to 128 MHz and the frequency span to 100 MHz.

➢ Press the FREQ key and enter 128 MHz.
➢ Press the SPAN key and enter 100 MHz.

4. Set the RF attenuation to 60 dB to attenuate the input signal or to increase

the intrinsic noise.

➢ Press the AMPT key.

Operating Manual 1164.4556.12 - 06 2.11

R&S FSP Getting Started

Measuring Signals in the Vicinity of Noise

➢ Press the RF ATTEN MANUAL softkey and enter 60 dB.

The RF attenuation indicator is marked with an asterisk (*Att 60 dB) to show
that it is no longer coupled to the reference level. The high input attenuation
reduces the reference signal which can no longer be detected in noise.

Fig. 2-1 Sinewave signal with low S/N ratio. The signal is measured with the auto-

peak detector and is completely swamped by the intrinsic noise of the
R&S FSP.

5. To suppress noise spikes the trace can be averaged.

➢ Press the TRACE key.
➢ Press the AVERAGE softkey.

The traces of consecutive sweeps are averaged. To perform averaging, the
R&S FSP automatically switches on the sample detector. The RF signal,
therefore, can be more clearly distinguished from noise.

Fig. 2-2 RF sinewave signal with low S/N ratio if the trace is averaged.

6. Instead of trace averaging, a video filter that is narrower than the resolution

bandwidth can be selected.

➢ Press the CLEAR/WRITE softkey in the trace menu.
➢ Press the BW key.

2.12 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Measuring Signals in the Vicinity of Noise

➢ Press the VIDEO BW MANUAL softkey and enter 10 kHz.

The RF signal can be more clearly distinguished from noise.

Fig. 2-3 RF sinewave signal with low S/N ratio if a smaller video bandwidth is

selected.

7. By reducing the resolution bandwidth by a factor of 10, the noise is reduced

by 10 dB.

➢ Press the RES BW MANUAL softkey and enter 300 kHz.

The displayed noise is reduced by approx. 10 dB. The signal, therefore,
emerges from noise by about 10 dB. Compared to the previous setting, the
video bandwidth has remained the same, i.e. it has increased relative to the
smaller resolution bandwidth. The averaging effect is, therefore, reduced by
the video bandwidth. The trace will be noisier.

Fig. 2-4 Reference signal at a smaller resolution bandwidth

Operating Manual 1164.4556.12 - 06 2.13

R&S FSP Getting Started

Noise Measurements

2.4 Noise Measurements

Noise measurements play an important role in spectrum analysis. Noise e.g. affects
the sensitivity of radio communication systems and their components.

Noise power is specified either as the total power in the transmission channel or as
the power referred to a bandwidth of 1 Hz. The sources of noise are, for example,
amplifier noise or noise generated by oscillators used for the frequency conversion
of useful signals in receivers or transmitters. The noise at the output of an amplifier
is determined by its noise figure and gain.

The noise of an oscillator is determined by phase noise near the oscillator frequency
and by thermal noise of the active elements far from the oscillator frequency. Phase
noise can mask weak signals near the oscillator frequency and make them impossi­ble to detect.

2.4.1 Measuring noise power density

To measure noise power referred to a bandwidth of 1 Hz at a certain frequency, the
R&S FSP has an easy-to-use marker function. This marker function calculates the
noise power density from the measured marker level.

2.4.1.1 Measurement example – Measuring the intrinsic noise power density of the
R&S FSP at 1 GHz and calculating the R&S FSP’s noise figure

1. Set the R&S FSP to its default state.

➢ Press the PRESET key.

The R&S FSP is in its default state.

2. Set the center frequency to 1 GHz and the span to 1 MHz.

➢ Press the FREQ key and enter 1 GHz.
➢ Press the SPAN key and enter 1 MHz.

3. Switch on the marker and set the marker frequency to 1 GHz.

➢ Press the MKR key and enter 1 GHz.

4. Switch on the noise marker function.

➢ Press the MEAS key.
➢ Press the NOISE MARKER softkey.

The R&S FSP displays the noise power at 1 GHz in dBm (1Hz).

Since noise is random, a sufficiently long measurement time has to be selected
to obtain stable measurement results. This can be achieved by averaging the
trace or by selecting a very small video bandwidth relative to the resolution
bandwidth.

5. The measurement result is stabilized by averaging the trace

➢ Press the TRACE key.
➢ Press the AVERAGE softkey.

The R&S FSP performs sliding averaging over 10 traces from consecutive
sweeps. The measurement result becomes more stable.

2.14 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Noise Measurements

Conversion to other reference bandwidths

The result of the noise measurement can be referred to other bandwidths by simple
conversion. This is done by adding 10 · log (BW) to the measurement result, BW
being the new reference bandwidth.

Example:

A noise power of –150 dBm (1 Hz) is to be referred to a bandwidth of 1 kHz.
P

= -150 + 10 · log (1000) = -150 +30 = -120 dBm(1 kHz)

[1kHz]

Calculation method:

The following method is used to calculate the noise power:

If the noise marker is switched on, the R&S FSP automatically activates the sample
detector. The video bandwidth is set to 1/10 of the selected resolution bandwidth
(RBW).

To calculate the noise, the R&S FSP takes an average over 17 adjacent pixels (the
pixel on which the marker is positioned and 8 pixels to the left, 8 pixels to the right of
the marker). The measurement result is stabilized by video filtering and averaging
over 17 pixels.

Since both video filtering and averaging over 17 trace points is performed in the log
display mode, the result would be 2.51 dB too low (difference between logarithmic
noise average and noise power). The R&S FSP, therefore, corrects the noise figure
by 2.51 dB.

To standardize the measurement result to a bandwidth of 1 Hz, the result is also cor­rected by –10 · log (RBW

), with RBW

noise

being the power bandwidth of the

noise

selected resolution filter (RBW).

Detector selection

The noise power density is measured in the default setting with the sample detector
and using averaging. Other detectors that can be used to perform a measurement
giving true results are the average detector or the RMS detector. If the average
detector is used, the linear video voltage is averaged and displayed as a pixel. If the
RMS detector is used, the squared video voltage is averaged and displayed as a
pixel. The averaging time depends on the selected sweep time (=SWT/501). An
increase in the sweep time gives a longer averaging time per pixel and thus stabi­lizes the measurement result. The R&S FSP automatically corrects the measure­ment result of the noise marker display depending on the selected detector (+1.05
dB for the average detector, 0 dΒ for the RMS detector). It is assumed that the video
bandwidth is set to at least three times the resolution bandwidth. While the average
or RMS detector is being switched on, the R&S FSP sets the video bandwidth to a
suitable value.

The Pos Peak, Neg Peak, Auto Peak and Quasi Peak detectors are not suitable for
measuring noise power density.

Operating Manual 1164.4556.12 - 06 2.15

R&S FSP Getting Started

Noise Measurements

Determining the noise figure:

The noise figure of amplifiers or of the R&S FSP alone can be obtained from the
noise power display. Based on the known thermal noise power of a 50 Ω resistor at
room temperature (-174 dBm (1Hz)) and the measured noise power P

noise

the noise

figure (NF) is obtained as follows:

NF = P

+ 174 – g,

noise

where g = gain of DUT in dB

Example:

The measured internal noise power of the R&S FSP at an attenuation of 0 dB is
found to be –153 dBm/1 Hz. The noise figure of the R&S FSP is obtained as follows

NF = -153 + 174 = 19 dB

If noise power is measured at the output of an amplifier, for example, the sum of
the internal noise power and the noise power at the output of the DUT is mea­sured. The noise power of the DUT can be obtained by subtracting the internal
noise power from the total power (subtraction of linear noise powers). By means
of the following diagram, the noise level of the DUT can be estimated from the
level difference between the total and the internal noise level.

Correction factor in dB

Total power/intrinsic noise power in dB

Fig. 2.15 Correction factor for measured noise power as a function of the ratio of total power to

the intrinsic noise power of the R&S FSP.

2.16 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Noise Measurements

2.4.2 Measurement of Noise Power within a Transmission Channel

Noise in any bandwidth can be measured with the channel power measurement
functions. Thus the noise power in a communication channel can be determined, for
example. If the noise spectrum within the channel bandwidth is flat, the noise marker
from the previous example can be used to determine the noise power in the channel
by considering the channel bandwidth. If, however, phase noise and noise that nor­mally increases towards the carrier is dominant in the channel to be measured, or if
there are discrete spurious signals in the channel, the channel power measurement
method must be used to obtain correct measurement results.

2.4.2.1 Measurement Example – Measuring the intrinsic noise of the R&S FSP at 1
GHz in a 1.23 MHz channel bandwidth with the channel power function

Test setup:

The RF input of the R&S FSP remains open-circuited or is terminated with 50 Ω.

Measurement with the R&S FSP:

1. Set the R&S FSP to its default state.

➢ Press the PRESET key.

The R&S FSP is in its default state.

2. Set the center frequency to 1 GHz and the span to 2 MHz.

➢ Press the FREQ key and enter 1 GHz.
➢ Press the SPAN key and enter 2 MHz.

3. To obtain maximum sensitivity, set RF attenuation on the R&S FSP to 0 dB.

➢ Press the AMPT key.
➢ Press the RF ATTEN MANUAL softkey and enter 0 dB.

4. Switch on and configure the channel power measurement.

➢ Press the MEAS key.
➢ Press the CHAN PWR ACP softkey.

The R&S FSP activates the channel or adjacent channel power measurement
according to the currently set configuration.

➢ Press the CP/ACP CONFIG ! softkey.

The R&S FSP enters the submenu for configuring the channel.

➢ Press the CHANNEL BANDWIDTH softkey and enter 1.23 MHz.

The R&S FSP displays the 1.23 MHz channel as two vertical lines which are
symmetrical to the center frequency.

➢ Press the PREV key.

The R&S FSP returns to the main menu for channel and adjacent channel
power measurement.

➢ Press the ADJUST SETTINGS softkey.

The settings for the frequency span, the bandwidth (RBW and VBW) and the
detector are automatically set to the optimum values required for the
measurement.

Operating Manual 1164.4556.12 - 06 2.17

R&S FSP Getting Started

Noise Measurements

Fig. 2-1 Measurement of the R&S FSP’s intrinsic noise power in a 1.23 MHz channel

bandwidth.

5. Stabilizing the measurement result by increasing the sweep time

➢ Press the SWEEP TIME softkey and enter 1 s.

By increasing the sweep time to 1 s, the trace becomes much smoother
thanks to the RMS detector and the channel power measurement display is
much more stable.

6. Referring the measured channel power to a bandwidth of 1 Hz

➢ Press the CHAN PWR / Hz softkey.

The channel power is referred to a bandwidth of 1 Hz. The measurement is
corrected by -10 · log (ChanBW), with ChanBW being the channel bandwidth
that was selected.

Method of calculating the channel power

When measuring the channel power, the R&S FSP integrates the linear power
which corresponds to the levels of the pixels within the selected channel. The
R&S FSP uses a resolution bandwidth which is far smaller than the channel band­width. When sweeping over the channel, the channel filter is formed by the pass­band characteristics of the resolution bandwidth (see Fig. 2.16).

-3 dB

Resolution filter

Sweep

Channel bandwith

Fig. 2.16 Approximating the channel filter by sweeping with a small resolution bandwidth

The following steps are performed:

2.18 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Noise Measurements

• The linear power of all the trace pixels within the channel is calculated.

= 10

i

(Li/10)

P
where
P

= power of the trace pixel i

i

L

= displayed level of trace point i

i

• The powers of all trace pixels within the channel are summed up and the sum is

divided by the number of trace pixels in the channel.

• The result is multiplied by the quotient of the selected channel bandwidth and the

noise bandwidth of the resolution filter (RBW).

Since the power calculation is performed by integrating the trace within the channel
bandwidth, this method is also called the IBW method (Integration Bandwidth
method).

Bandwidth selection (RBW)

For channel power measurements, the resolution bandwidth (RBW) must be small
compared to the channel bandwidth, so that the channel bandwidth can be defined
precisely. If the resolution bandwidth which has been selected is too wide, this may
have a negative effect on the selectivity of the simulated channel filter and result in
the power in the adjacent channel being added to the power in the transmit channel.
A resolution bandwidth equal to 1% to 3% of the channel bandwidth should, there­fore, be selected. If the resolution bandwidth is too small, the required sweep time
becomes too long and the measurement time increases considerably.

Detector selection

Since the power of the trace is measured within the channel bandwidth, only the
sample detector and RMS detector can be used. These detectors provide measured
values that make it possible to calculate the real power. The peak detectors (Pos
Peak, Neg Peak and Auto Peak) are not suitable for noise power measurements as
no correlation can be established between the peak value of the video voltage and
power.

With the sample detector, a value (sample) of the IF envelope voltage is displayed
at each trace pixel. Since the frequency spans are very large compared with the res­olution bandwidth (span/RBW >501), sinewave signals present in the noise might be
lost, i.e. they are not displayed. This is not important for pure noise signals, however,
since a single sample in itself is not important - it is the probability distribution of all
measured values that counts. The number of samples for power calculation is lim­ited to the number of trace pixels (501 for the R&S FSP).

To increase the repeatability of measurements, averaging is often carried out
over several traces (AVERAGE softkey in the TRACE menu). This gives spuri-
ous results for channel power measurements (max. –2.51 dB for ideal averag­ing). Trace averaging should, therefore, be avoided.

Operating Manual 1164.4556.12 - 06 2.19

R&S FSP Getting Started

Noise Measurements

With the RMS detector, the whole IF envelope is used to calculate the power for
each trace pixel. The IF envelope is digitized using a sampling frequency which is at
least five times the resolution bandwidth which has been selected. Based on the
sample values, the power is calculated for each trace pixel using the following for­mula:

N

1

P

RMS

s

= linear digitized video voltage at the output of the A/D converter

i

----

N

2

×=

s

i

∑

i1=

N = number of A/D converter values per pixel of the trace

= power represented by a trace pixel

P

RMS

When the power has been calculated, the power units are converted into decibels
and the value is displayed as a trace pixel.

The number of A/D converter values, N, used to calculate the power, is defined by
the sweep time. The time per trace pixel for power measurements is directly propor­tional to the selected sweep time. The RMS detector uses far more samples for
power measurement than the sample detector, especially if the sweep time is
increased. The measurement uncertainty can be reduced considerably. In the
default setting, the R&S FSP therefore uses the RMS detector to measure the chan­nel power.

For both detectors (sample and RMS), the video bandwidth (VBW) must at least be
three times the resolution bandwidth, so that the peak values of the video voltage
are not cut off by the video filter. At smaller video bandwidths, the video signal is
averaged and the power readout will be too small.

Sweep time selection

If the sample detector is used, it is best to select the smallest sweep time possible
for a given span and resolution bandwidth. The minimum time is obtained if the set­ting is coupled. This means that the time per measurement is minimal. Extending
the measurement time does not have any advantages as the number of samples for
calculating the power is defined by the number of trace pixels in the channel.

When using the RMS detector, the repeatability of the measurement results can be
influenced by the selection of sweep times. Repeatability is increased at longer
sweep times.

Repeatability can be estimated from the following diagram:

2.20 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Noise Measurements

max. error/dB

0

95 % Confidence

0.5

1

1.5

2

2.5

level

99 % Confidence

level

3

10

Fig. 2.17 Repeatability of channel power measurements as a function of the number of samples

used for power calculation

100

1000

10000

Number of samples

100000

The curves in Fig. 2.17 indicates the repeatability obtained with a probability of 95%
and 99% depending on the number of samples used.

The repeatability with 600 samples is ± 0.5 dB. This means that – if the sample
detector and a channel bandwidth over the whole diagram (channel bandwidth =
span) is used – the measured value lies within ± 0.5 dB of the true value with a prob­ability of 99%.

If the RMS detector is used, the number of samples can be estimated as follows:

Since only uncorrelated samples contribute to the RMS value, the number of sam­ples can be calculated from the sweep time and the resolution bandwidth.

Samples can be assumed to be uncorrelated if sampling is performed at intervals of
1/RBW. The number of uncorrelated samples (N

= SWT × RBW

N

decorr

The number of uncorrelated samples per trace pixel is obtained by dividing N

) is calculated as follows:

decorr

decorr

by 501 (= pixels per trace).

Example:

At a resolution bandwidth of 30 kHz and a sweep time of 100 ms, 3000 uncorrelated
samples are obtained. If the channel bandwidth is equal to the frequency display
range, i.e. all trace pixels are used for the channel power measurement, a repeat­ability of 0.2 dB with a confidence level of 99% is the estimate that can be derived
from Fig. 2.17.

Operating Manual 1164.4556.12 - 06 2.21

R&S FSP Getting Started

Noise Measurements

2.4.3 Measuring Phase Noise

The R&S FSP has an easy-to-use marker function for phase noise measurements.
This marker function indicates the phase noise of an RF oscillator at any carrier in
dBc in a bandwidth of 1 Hz.

2.4.3.1 Measurement Example – Measuring the phase noise of a signal generator at a
carrier offset of 10 kHz

Test setup:

Signal

generator

FSP

Settings on the signal generator (e.g. R&S SMIQ):

Frequency: 100 MHz

Level: 0 dBm

Measurement using R&S FSP:

1. Set the R&S FSP to its default state

➢ Press the PRESET key.

R&S FSP is in its default state.

2. Set the center frequency to 100 MHz and the span to 50 kHz

➢ Press the FREQ key and enter 100 MHz.
➢ Press the SPAN key and enter 50 kHz.

3. Set the R&S FSP’s reference level to 0 dBm (=signal generator level)

➢ Press the AMPT key and enter 0 dBm.

4. Enable phase noise measurement

➢ Press the MKR FCTN key.
➢ Press the PHASE NOISE ! softkey.

The R&S FSP activates phase noise measurement. Marker 1 (=main marker)
and marker 2 (= delta marker) are positioned on the signal maximum. The
position of the marker is the reference (level and frequency) for the phase
noise measurement. A horizontal line represents the level of the reference
point and a vertical line the frequency of the reference point. Data entry for the
delta marker is activated so that the frequency offset at which the phase noise
is to be measured can be entered directly.

5. 10 kHz frequency offset for determining phase noise.

➢ Enter 10 kHz.

The R&S FSP displays the phase noise at a frequency offset of 10 kHz. The
magnitude of the phase noise in dBc/Hz is displayed in the delta marker output
field at the top right of the screen (delta 2 [T1 PHN]).

2.22 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Measurements on Modulated Signals

6. Stabilize the measurement result by activating trace averaging.

➢ Press the TRACE key.
➢ Press the AVERAGE softkey.

Fig. 2-1 Measuring phase noise with the phase-noise marker function

The frequency offset can be varied by moving the marker with the spinwheel
or by entering a new frequency offset as a number.

2.5 Measurements on Modulated Signals

If RF signals are used to transmit information, an RF carrier is modulated. Analog
modulation methods such as amplitude modulation, frequency modulation and
phase modulation have a long history and digital modulation methods are now used
for modern systems. Measuring the power and the spectrum of modulated signals is
an important task to assure transmission quality and to ensure the integrity of other
radio services. This task can be performed easily with a Spectrum Analyzer. Modern
Spectrum Analyzers also provide the test routines that are essential to simplify com­plex measurements.

2.5.1 Measurements on AM signals

The R&S FSP detects the RF input signal and displays the magnitudes of its compo­nents as a spectrum. AM modulated signals are also demodulated by this process.
The AF voltage can be displayed in the time domain if the modulation sidebands are
within the resolution bandwidth. In the frequency domain, the AM sidebands can be
resolved with a small bandwidth and can be measured separately. This means that
the modulation depth of a carrier modulated with a sinewave signal can be mea­sured. Since the dynamic range of a Spectrum Analyzer is very wide, even
extremely small modulation depths can be measured accurately. The R&S FSP has
a test routine which measures the modulation depth in %.

Operating Manual 1164.4556.12 - 06 2.23

R&S FSP Getting Started

Measurements on Modulated Signals

2.5.1.1 Measurement Example 1 – Displaying the AF of an AM signal in the time
domain

Test setup:

Signal

generator

FSP

Settings on the signal generator (e.g. R&S SMIQ):

Frequency: 100 MHz

Level: 0 dBm

Modulation: 50 % AM, 1 kHz AF

Measurement with the R&S FSP:

1. Set the R&S FSP to its default state

➢ Press the PRESET key.

The R&S FSP is in its default state.

2. Set the center frequency to 100 MHz and the span to 0 kHz

➢ Press the FREQ key and enter 100 MHz.
➢ Press the SPAN key and enter 0 Hz.

3. Set the reference level to +6 dBm and the display range to linear

➢ Press the AMPT key and enter 6 dBm.
➢ Press the RANGE LINEAR softkey.

4. Use the video trigger to trigger on the AF signal in order to obtain a

stationary display

➢ Press the TRIG key.
➢ Press the VIDEO softkey.

The video trigger level is set to 50% if the instrument is switched on for the first
time. The trigger level is displayed as a horizontal line across the graph. The
R&S FSP displays the 1 kHz AF signal stably in the time domain.

2.24 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Measurements on Modulated Signals

Fig. 2-2 Measuring the AF signal from a 1 kHz AM carrier

If the R&S FSP is equipped with the AM/FM Demodulator option (R&S FSP­B3), the AF can be monitored on the built-in loudspeaker.

5. Switch on the internal AM demodulator

➢ Press the MKR FCTN key.
➢ Press the MKR DEMOD softkey.

The R&S FSP switches the AM demodulator on automatically.

➢ Turn up volume control.

A 1 kHz tone is output by the built-in loudspeaker.

2.5.1.2 Measurement Example 2 – Measuring the modulation depth of an AM carrier in
the frequency domain

Test setup:

Signal

generator

FSP

Settings on the signal generator (e.g. R&S SMIQ):

Frequency: 100 MHz

Level: -30 dBm

Modulation: 50 % AM, 1 kHz AF

Measurement with the R&S FSP:

1. Set the R&S FSP to its default state

➢ Press the PRESET key.

The R&S FSP is in its default state.

2. Set the center frequency to 100 MHz and the span to 0 kHz

➢ Press the FREQ key and enter 100 MHz.

Operating Manual 1164.4556.12 - 06 2.25

R&S FSP Getting Started

Measurements on Modulated Signals

➢ Press the SPAN key and enter 5 kHz.

3. Activate the marker function for AM depth measurement

➢ Press the MEAS key.
➢ Press the MODULATION DEPTH softkey.

The R&S FSP automatically positions a marker on the carrier signal in the
middle of the graph and one delta marker on each of the lower and upper AM
sidebands. The R&S FSP calculates the AM modulation depth from the ratios
of the delta marker levels to the main marker level and outputs the numerical
value in the marker info field

Fig. 2-3 Measurement of AM modulation depth. The modulation depth is indicated

by MDEPTH = 49.346 %. The frequency of the AF signal is indicated by the
delta markers

2.5.2 Measurements on FM Signals

Since Spectrum Analyzers only display the magnitude of signals by means of the
envelope detector, the modulation of FM signals cannot be directly measured as is
the case with AM signals. With FM signals, the voltage at the output of the envelope
detector is constant as long as the frequency deviation of the signal is within the flat
part of the passband characteristic of the resolution filter which has been selected.
Amplitude variations can only occur if the current frequency lies on the falling edge
of the filter characteristic. This effect can be used to demodulate FM signals. The
center frequency of the R&S FSP is set in a way that the nominal frequency of the
test signal is on the filter edge (below or above the center frequency). The resolution
bandwidth and the frequency offset are selected in a way that the current frequency
is on the linear part of the filter slope. The frequency variation of the FM signal is
then transformed into an amplitude variation which can be displayed in the time
domain.

The R&S FSP's analog 4
have a good filter-slope linearity, if the frequency of the R&S FSP is set to 1.2 times
the filter bandwidth below or above the frequency of the transmit signal. The useful
range for FM demodulation is then almost equal to the resolution bandwidth.

th

order filters with frequencies from 300 kHz to 3 MHz

2.26 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Measurements on Modulated Signals

2.5.2.1 Measurement Example – Displaying the AF of an FM carrier

Test setup:

Signal

generator

FSP

Settings on the signal generator (e.g. R&S SMIQ):

Frequency: 100 MHz

Level: -30 dBm

Modulation: FM 0 kHz deviation (i.e., FM = off), 1 kHz AF

Measurement with the R&S FSP:

1. Set the R&S FSP to its default state

➢ Press the PRESET key.

The R&S FSP is in its default state.

2. Set the center frequency to 99.64 MHz and the span to 300 kHz.

➢ Press the FREQ key and enter 99.64 MHz.
➢ Press the SPAN key and enter 300 kHz.

3. Set a resolution bandwidth of 300 kHz.

➢ Press the BW key.
➢ Press the RES BW MANUAL softkey and enter 300 kHz.

4. Set a display range of 20 dB and shift the filter characteristics to the middle

of the display.

➢ Press the AMPT key.
➢ Press the RANGE LOG MANUAL softkey and enter 20 dB.
➢ Press the NEXT key.
➢ Set the GRID softkey to REL.
➢ Press the PREV softkey.
➢ Using the spinwheel, shift the reference level so that the filter edge intersects

the - 10 dB level line at the center frequency.

The slope of the 300 kHz filter is displayed. This corresponds to the
demodulator characteristics for FM signals with a slope of approx. 5 dB/100
kHz.

Operating Manual 1164.4556.12 - 06 2.27

R&S FSP Getting Started

Measurements on Modulated Signals

Fig. 2-4 Filter edge of a 300 kHz filter used as an FM-discriminator characteristic

5. Set an FM deviation of 100 kHz and an AF of 1 kHz on the signal generator

6. Set a frequency deviation of 0 Hz on the R&S FSP

➢ Press the SPAN key.
➢ Press the ZERO SPAN.

The demodulated FM signal is displayed. The signal moves across the screen.

7. Creating a stable display by video triggering

➢ Press the TRIG key.
➢ Press the VIDEO softkey.

A stationary display is obtained for the FM AF signal

Result: (-10 ± 5) dB; this means that a deviation of 100 kHz is obtained if the demod­ulator characteristic slope is 5 dB/100 kHz

Fig. 2.18 Demodulated FM signal

2.28 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Measurements on Modulated Signals

2.5.3 Measuring Channel Power and Adjacent Channel Power

Measuring channel power and adjacent channel power is one of the most important
tasks in the field of digital transmission for a Spectrum Analyzer with the necessary
test routines. While, theoretically, channel power could be measured at highest
accuracy with a power meter, its low selectivity means that it is not suitable for mea­suring adjacent channel power as an absolute value or relative to the transmit chan­nel power. The power in the adjacent channels can only be measured with a
selective power meter.

A Spectrum Analyzer cannot be classified as a true power meter, because it displays
the IF envelope voltage. However, it is calibrated such as to correctly display the
power of a pure sinewave signal irrespective of the selected detector. This calibra­tion is not valid for non-sinusoidal signals. Assuming that the digitally modulated sig­nal has a Gaussian amplitude distribution, the signal power within the selected
resolution bandwidth can be obtained using correction factors. These correction fac­tors are normally used by the Spectrum Analyzer's internal power measurement rou­tines in order to determine the signal power from IF envelope measurements. These
factors are valid if and only if the assumption of a Gaussian amplitude distribution is
correct.

Apart from this common method, the R&S FSP also has a true power detector, i.e.
an RMS detector. It correctly displays the power of the test signal within the selected
resolution bandwidth irrespective of the amplitude distribution, without additional
correction factors being required. With an absolute measurement uncertainty of <

0.5 dB and a relative measurement uncertainty of < 0.2 dB (each with a confidence
level of 95%), the R&S FSP comes close to being a true power meter.

There are two possible methods for measuring channel and adjacent channel power
with a Spectrum Analyzer:

The IBW method (Integration Bandwidth Method) in which the R&S FSP measures
with a resolution bandwidth that is less than the channel bandwidth and integrates
the level values of the trace versus the channel bandwidth. This method is described
in the section on noise measurements.

Measurement using a channel filter.

In this case, the R&S FSP makes measurements in the time domain using an IF fil­ter that corresponds to the channel bandwidth. The power is measured at the output
of the IF filter. Until now, this method has not been used for Spectrum Analyzers,
because channel filters were not available and the resolution bandwidths, optimized
for the sweep, did not have a sufficient selectivity. The method was reserved for spe­cial receivers optimized for a particular transmission method.

The R&S FSP has test routines for simple channel and adjacent channel power
measurements. These routines give quick results without any complex or tedious
setting procedures.

Operating Manual 1164.4556.12 - 06 2.29

R&S FSP Getting Started

Measurements on Modulated Signals

2.5.3.1 Measurement Example 1 – ACPR measurement on an IS95 CDMA Signal

Test setup:

Signal

generator

FSP

Settings on the signal generator (e.g. R&S SMIQ):

Frequency: 850 MHz

Level: 0 dBm

Modulation: CDMA IS 95

Measurement with the R&S FSP:

1. Set the R&S FSP to its default state.

➢ Press the PRESET key.

The R&S FSP is in its default state.

2. Set the center frequency to 850 MHz and frequency deviation to 4 MHz.

➢ Press the FREQ key and enter 850 MHz.

3. Set the reference level to +10 dBm.

➢ Press the AMPT key and enter 10 dBm.

4. Configuring the adjacent channel power for the CDMA IS95 reverse link.

➢ Press the MEAS key.
➢ Press the CHAN PWR ACP ! softkey.
➢ Press the CP/ACP STANDARD softkey.

From the list of standards, select CDMA IS95A REV using the spinwheel or the
cursor down key below the spinwheel and press ENTER.

The R&S FSP sets the channel configuration according to the IS95 standard
for mobile stations with 2 adjacent channels above and below the transmit
channel. The spectrum is displayed in the upper part of the screen, the numeric
values of the results and the channel configuration in the lower part of the
screen. The various channels are represented by vertical lines on the graph.
The frequency span, resolution bandwidth, video bandwidth and detector are
selected automatically to give correct results. To obtain stable results ­especially in the adjacent channels (30 kHz bandwidth) which are narrow in
comparison with the transmission channel bandwidth (1.23 MHz) - the RMS
detector is used.

2.30 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Measurements on Modulated Signals

5. Set the optimal reference level and RF attenuation for the applied signal

level.

➢ Press the ADJUST REF LVL softkey.

The R&S FSP sets the optimal RF attenuation and the reference level based
on the transmission channel power to obtain the maximum dynamic range.
The following figure shows the result of the measurement.

Fig. 2-1 Adjacent channel power measurement on a CDMA IS95 signal

The repeatability of the results, especially in the narrow adjacent channels,
strongly depends on the measurement time since the dwell time within the 30
kHz channels is only a fraction of the complete sweep time. A longer sweep
time may increase the probability that the measured value converges to the
true value of the adjacent channel power, but this increases measurement
time.

To avoid long measurement times, the R&S FSP measures the adjacent
channel power in the time domain (FAST ACP). In the FAST ACP mode, the
R&S FSP measures the power of each channel at the defined channel
bandwidth, while being tuned to the center frequency of the channel in
question. The digital implementation of the resolution bandwidths makes it
possible to select a filter characteristics that is precisely tailored to the signal.
In case of CDMA IS95, the power in the useful channel is measured with a
bandwidth of 1.23 MHz and that of the adjacent channels with a bandwidth of
30 kHz. Therefore the R&S FSP jumps from one channel to the other and
measures the power at a bandwidth of 1.23 MHz or 30 kHz using the RMS
detector. The measurement time per channel is set with the sweep time. It is
equal to the selected measurement time divided by the selected number of
channels. The five channels from the above example and the sweep time of
100 ms give a measurement time per channel of 20 ms.

Compared to the measurement time per channel given by the span (= 5 MHz)
and sweep time (= 100 ms, equal to 0.600 ms per 30 kHz channel) used in the
example, this is a far longer dwell time on the adjacent channels (factor of 12).
In terms of the number of uncorrelated samples this means 20000/33 µs = 606
samples per channel measurement compared to 600/33µs = 12.5 samples per
channel measurement.

Repeatability with a confidence level of 95% is increased from ± 1.4 dB to ±

0.38 dB as shown in Fig. 2.17. For the same repeatability, the sweep time
would have to be set to 1.2 s with the integration method. The following figure
shows the standard deviation of the results as a function of the sweep time.

Operating Manual 1164.4556.12 - 06 2.31

R&S FSP Getting Started

Measurements on Modulated Signals

ACPR Repeatability IS95

IBW Method

1,4

1,2

1

0,8

0,6

Standard dev / dB

0,4

0,2

0

10 100 1000

Alternate channels

Adjacent channels

Tx chann el

Sweep time/ms

Fig. 2-2 Repeatability of adjacent channel power measurement on IS95-standard

signals if the integration bandwidth method is used

6. Switch to Fast ACP to increase the repeatability of results.

➢ Press the CP/ACP CONFIG ! softkey.
➢ Set the FAST ACP softkey to ON.
➢ Press the ADJUST REF LVL softkey.

The R&S FSP measures the power of each channel in the time domain. The
trace represents power as a function of time for each channel (see Fig. 2-3).
The numerical results over consecutive measurements become much more
stable.

Fig. 2-3 Measuring the channel power and adjacent channel power ratio for IS95

signals in the time domain (Fast ACP)

The following figure shows the repeatability of power measurements in the
transmit channel and of relative power measurements in the adjacent channels
as a function of sweep time. The standard deviation of measurement results is
calculated from 100 consecutive measurements as shown in Fig. 2-2. Take
scaling into account if comparing power values.

2.32 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Measurements on Modulated Signals

ACPR IS95 Repeatability

0,35

0,3

0,25

0,2

0,15

Standard dev /dB

0,1

0,05

0

10 100 1000

Tx channel

Alternate channels

Adjacent channels

Sweep time/ms

Fig. 2-4 Repeatability of adjacent channel power measurements on IS95 signals in

the Fast ACP mode

Note on adjacent channel power measurements on IS95 base-station sig­nals:

When measuring the adjacent channel power of IS95 base-station signals, the
frequency spacing of the adjacent channel to the nominal transmit channel is
specified as ±750 kHz. The adjacent channels are, therefore, so close to the
transmit channel that the power of the transmit signal leaks across and is also
measured in the adjacent channel if the usual method using the 30 kHz resolu­tion bandwidth is applied. The reason is the low selectivity of the 30 kHz resolu­tion filter. The resolution bandwidth, therefore, must be reduced considerably,
e.g. to 3 kHz to avoid this. This causes very long measurement times (factor of
100 between a 30 kHz and 3 kHz resolution bandwidth).

This effect is avoided with the time domain method which uses steep IF filters.
The 30 kHz channel filter implemented in the R&S FSP has a very high selectivity
so that even with a ±750 kHz spacing to the transmit channel the power of the
useful modulation spectrum is not measured.

The following figure shows the passband characteristics of the 30 kHz channel filter
in the R&S FSP.

Fig. 2.19 Frequency response of the 30 kHz channel filter for measuring the power in the IS 95

adjacent channel

Operating Manual 1164.4556.12 - 06 2.33

R&S FSP Getting Started

Measurements on Modulated Signals

2.5.3.2 Measurement Example 2 – Measuring the adjacent channel power of an IS136
TDMA signal

Test setup:

Signal

generator

Ext Ref Out

RF Inp

FSP

Ext Ref IN

As the modulation spectrum of the IS136 signal leaks into the adjacent channel, it
makes a contribution to the power in the adjacent channel. Exact tuning of the
R&S FSP to the transmit frequency is therefore critical. If tuning is not precise,
the adjacent channel power ratios in the lower and upper adjacent channels
become asymmetrical. The R&S FSP’s frequency and the generator frequency
are therefore synchronized.

Settings on the signal generator (e.g. R&S SMIQ):

Frequency: 850 MHz

Level: -20 dBm

Modulation: IS136/NADC

Measurement with the R&S FSP

1. Set the R&S FSP to its default state.

➢ Press the PRESET key.

The R&S FSP is in its default state.

2. Set up the R&S FSP for synchronization to an external reference frequency.

➢ Press the SETUP key.
➢ Set the REFERENCE softkey to EXT.

3. Set the center frequency to 850 MHz-

Press the FREQ key and enter 850 MHz.

4. Configure adjacent channel power measurement for IS136 signals.

➢ Press the MEAS key.
➢ Press the CHAN PWR ACP ! softkey.
➢ Press the CP/ACP STANDARD softkey.
➢ Select NADC IS136 from the list of standards and press ENTER.

The R&S FSP performs the power measurement in 5 channels (in the useful
channel and in the two upper and two lower adjacent channels).

2.34 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Measurements on Modulated Signals

5. Setting the optimum reference level and RF attenuation for the

measurement

➢ Press the ADJUST REF LEVEL softkey.

The R&S FSP sets the optimum RF attenuation and the optimum reference
level on the basis of the measured channel power.

Fig. 2-1 Measuring the relative adjacent channel power of an NADC signal in each

of the two adjacent channels below and above the transmit channel.

To increase repeatability – especially in the adjacent channels – the R&S FSP’s Fast
ACP routine is recommended.

6. Switching on the Fast ACP routine.

➢ Press the CP/ACP CONFIG ! softkey
➢ Set the FAST ACP softkey to ON.

➢ Press the ADJUST REF LEVEL softkey.

The R&S FSP makes consecutive measurements on the 5 channels in the
Zero Span mode using the receive filter specified in IS 136 to define the
resolution bandwidth. The power in each channel is displayed on the graph as
a function of time

Operating Manual 1164.4556.12 - 06 2.35

R&S FSP Getting Started

Measurements on Modulated Signals

Fig. 2-2 Measuring adjacent channel power in time domain (Fast ACP)

As the resolution bandwidth is much wider than the one used for the integration
method, the results are much more stable when compared at the same sweep
time.

Repeatability can be influenced by the selected sweep time. The results
become much more stable if long sweep times are selected. Since the
amplitude distribution is different in different channels (part of the modulation
spectrum falls within the first adjacent channel), the repeatability depends on
the spacing of the measured channel from the transmit channel.

Fig. 2-3 below shows the standard deviation of results in the different channels

as a function of the selected sweep time. The standard deviation for the
various sweep times was recorded using a signal generator as a source. With
real DUTs the amplitude distributions in adjacent channels may be different so
that the standard deviation could differ from that shown in Fig. 2-3. To evaluate
the correct measuring time for time-critical measurements at a given standard
deviation, the standard deviation of the ACP values at the output of the real
DUT must be determined.

NADC Repeata bility

1.4

1.2

1

Standard Deviation / dB

0.8

0.6

0.4

0.2

Alt1 Channels

Tx Channel

Adj Channels

0

10 100 1000

Fig. 2-3 Standard deviation of the results of Fast ACP measurement as a function of

selected sweep time evaluated from 100 measurements per sweep time

Swe ep Tim e / m s

2.36 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Measurements on Modulated Signals

2.5.3.3 Measurement Example 3 – Measuring the Modulation Spectrum in Burst Mode
with the Gated Sweep Function

Since transmission systems compliant to IS136 use a TDMA method, the adjacent
channel power must also be measured in burst mode. An IS136 TDMA frame is
divided into 6 time slots. Two of these slots are assigned to a subscriber. This
means that the ratio of transmit time to off-time for IS136 mobile phones is only 1:3
(e.g. time slots 1 and 4)

The R&S FSP supports the measurement of the adjacent channel power in the
TDMA mode with the Gated Sweep function.

Test setup with the R&S Signal Generator SMIQ:

Trigger1

RF Inp

Ext Gate/Trig IN

FSP

Ext Ref INExt Ref Out

Par Data Output

Signal

generator

SMIQ

SMIQ-Z5

The R&S SMIQ has to be equipped with options R&S SMIQ-B10 or R&S SMIQ-B20
(modulation coder) and R&S SMIQ-B11 (data generator).

Option R&S SMIQ-Z5 is required to trigger the R&S FSP. This option is connected
to the R&S SMIQ’s parallel output port. The BNC output Trigger 1 of the R&S SMIQ­Z5 provides a TTL trigger signal on the rising edge of the IS136 burst, which is used
to start the R&S FSP sweep in the Gated Sweep mode.

The R&S FSP’s IF power trigger is not suitable for IS136. It triggers on every
level edge of the input signal. Since the modulation of the IS136 signal causes
level dips even during the transmit burst, there is no way of ensuring that the
R&S FSP is only triggered on the burst edge.

Settings on signal generator R&S SMIQ:

Switch the signal generator to the IS136 burst mode (time slots 1 and 4 are switched
on, the other time slots are switched off).

The R&S SMIQ is set as follows to generate the signal:

➢ Press the PRESET key.
➢ Press the FREQ key and enter 850 MHz.
➢ Press the LEVEL key and enter -20 dBm.
➢ Press the RETURN key.
➢ Select DIGITAL STANDARD using the spinwheel and press the SELECT key.
➢ Select NADC using the spinwheel and press the SELECT key.
➢ Press the SELECT key.
➢ Select ON using the spinwheel and press the SELECT key.
➢ Press the RETURN key.

Operating Manual 1164.4556.12 - 06 2.37

R&S FSP Getting Started

Measurements on Modulated Signals

➢ Keep turning the spinwheel until SAVE/RECALL FRAME appears in the list and

select the menu item SAVE/RECALL FRAME using the SELECT key.

➢ The cursor is set to GET PREDEFINED FRAME.
➢ Press the SELECT key.
➢ Select UP1TCH using the spinwheel and press the SELECT key.

In the following operating sequence for the R&S FSP, it is assumed that steps 1 to 6
of the previous example (“Measurement Example 2 – Measuring the adjacent chan-

nel power of an IS136 TDMA signal”) have already been performed.

1. Configuring the Gated Sweep function on the R&S FSP.

➢ Press the TRIG key.
➢ Press the GATED TRIGGER softkey.
➢ Press the EXTERN softkey.
➢ Press the GATE SETTINGS ! softkey.

The R&S FSP switches to time domain measurement so that the setting of the
Gated Sweep parameters can be checked visually.

➢ Press the SWEEPTIME softkey and enter 10 ms.

Exactly one TDMA burst will be displayed.

➢ Press the GATE DELAY softkey and enter 2 ms or set the Gate Delay using

the spinwheel so that the burst is reliably detected.

➢ Press the GATE LENGTH softkey and enter 5 ms or set the vertical line for the

gate length using the spinwheel so that the burst is reliably detected.

Fig. 2-4 Setting the parameters Gate Delay and Gate Length in time domain. The

time interval required to measure the spectrum is indicated by two vertical
lines.

➢ Press the PREV key.

The R&S FSP now performs the ACP measurement only during the switch-on
phase of the TDMA burst. The measurement is stopped during the switch-off
phase.

2.38 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Measurements on Modulated Signals

The selected sweep time is the net sweep time, i.e. the time during which the
R&S FSP is actually measuring. The complete frame of an IS136 signal takes 40
ms. In the above example, measurement only takes place for 2x5 ms within a
frame. The R&S FSP is therefore only measuring for 25% of the frame duration.
The total measuring time is therefore four times that for the CW mode.

2.5.3.4 Measurement Example 4 – Measuring the Transient Spectrum in Burst Mode
with the Fast ACP function

In addition to the modulation spectrum or adjacent channel power from the modula­tion of the RF carrier, the spectrum or adjacent channel power generated by burst
edges is also to be measured in TDMA systems. The spectrum is a pulse spectrum
and must be measured with the peak detector. With the usual IBW method, only the
power of the continuously modulated signal can be measured properly. Even if the
modulation spectrum is transmitted in the TDMA mode, the measurement of the
modulation spectrum will work because the burst edges are blanked out for the
measurement by means of the Gated Sweep function. The R&S FSP performs mea­surements only if the modulation spectrum is continuous when the burst is on.

However, the IBW method fails for the spectrum created by the burst edges. As the
measurement is carried out with resolution bandwidths that are very small compared
to the signal bandwidth, a spurious amplitude distribution is obtained in the defined
measurement channel because of the resolution bandwidth. The small resolution
bandwidth cannot settle to the peak amplitudes of the test signal. This problem is
avoided in the R&S FSP by performing time domain measurements with the root
raised cosine filter specified in the IS136 standard.

If the peak detector is used instead of the default RMS detector (which is selected
when the standard is selected), the true adjacent channel power generated by the
burst edges can also be measured.

Test setup:

The test setup for this example and the settings for R&S SMIQ are identical to those
in the previous example.

Measurement with the R&S FSP:

1. Set the R&S FSP to its default state.

➢ Press the PRESET key.

The R&S FSP is in its default state.

2. Synchronize the R&S FSP to an external reference frequency.

➢ Press the SETUP key.
➢ Set the REFERENCE softkey to EXT.

3. Set the center frequency to 850 MHz

➢ Press the FREQ key and enter 850 MHz.

4. Configure the adjacent channel power measurement for IS136 signals in

Fast ACP mode.

➢ Press the MEAS key.
➢ Press the CHAN PWR ACP ! softkey.

Operating Manual 1164.4556.12 - 06 2.39

R&S FSP Getting Started

Measurements on Modulated Signals

➢ Press the CP/ACP STANDARD softkey.
➢ Select NADC IS136 from the list of standards and press ENTER.
➢ Press the CP/ACP CONFIG ! softkey.
➢ Set the FAST ACP softkey to ON.

The R&S FSP performs the power measurement in 5 channels (in the useful
channel and in the two upper and lower adjacent channels).

5. Set the optimum reference level and RF attenuation for the measurement.

➢ Press the ADJUST REF LEVEL softkey.

The R&S FSP sets the optimum RF attenuation and the optimum reference
level on the basis of the measured channel power.

6. Select the peak detector and increase the sweep time to 10 s.

➢ Press the TRACE key.
➢ Press the DETECTOR softkey.
➢ Press the DETECTOR MAX PEAK softkey.
➢ Press the SWEEP key.
➢ Press the SWEEP TIME softkey and enter 10 s.

The R&S FSP measures the adjacent channel power generated by the burst
edges and the modulation.

Fig. 2-5 Adjacent channel power due to modulation spectrum and transient spec-

trum

The peak power display depends on the selected sweep time. The longer the
sweep time, the higher the probability of measuring the highest peak amplitude of
the signal.

With shorter sweep times, level dips can be seen in the time domain traces.
These level dips come from the burst characteristics of the signal. The numerical
results, however, indicate the peak amplitudes during the measurement in the
corresponding channel.

2.40 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Measurements on Modulated Signals

2.5.3.5 Measurement Example 5 – Measuring adjacent channel power of a W-CDMA
uplink signal

Test setup:

Signal

generator

FSP

Settings on the signal generator (e.g. R&S SMIQ):

Frequency: 1950 MHz

Level: 4 dBm

Modulation: 3 GPP W-CDMA Reverse Link

Measurement with the R&S FSP:

1. Set the R&S FSP to its default state.

➢ Press the PRESET key.

The R&S FSP is in its default state.

2. Set the center frequency to 1950 MHz.

➢ Press the FREQ key and enter 1950 MHz.

3. Switch on the ACP measurement for W-CDMA.

➢ Press the MEAS key.
➢ Press the CHAN PWR ACP ! softkey.
➢ Press the CP/ACP STANDARD softkey.
➢ From the list of standards, select W-CDMA 3GPP REV using the spinwheel or

the cursor down key below the spinwheel and press ENTER.
The R&S FSP sets the channel configuration to the 3GPP W-CDMA standard
for mobiles with two adjacent channels above and below the transmit channel.
The frequency span, the resolution and video bandwidth and the detector are
automatically set to the correct values. The spectrum is displayed in the upper
part of the screen and the channel power, the level ratios of the adjacent
channel powers and the channel configuration in the lower part of the screen.
The individual channels are displayed as vertical lines on the graph.

4. Set the optimum reference level and the RF attenuation for the applied

signal level.

➢ Press the ADJUST REF LEVEL softkey.

The R&S FSP sets the optimum RF attenuation and the reference level for the
power in the transmission channel to obtain the maximum dynamic range. The
following figure shows the result of the measurement:

Operating Manual 1164.4556.12 - 06 2.41

R&S FSP Getting Started

Measurements on Modulated Signals

Fig. 2-6 Measuring the relative adjacent channel power on a W-CDMA uplink signal

5. Measuring adjacent channel power with the Fast ACP method.

➢ Press the CP/ACP CONFIG ! softkey.
➢ Set FAST ACP softkey to ON.
➢ Press the ADJUST REF LVL softkey.

The R&S FSP measures the power of the individual channels in the time
domain. A root raised cosine filter with the parameters α = 0.22 and chip rate

3.84 Mcps (= receive filter for 3GPP W-CDMA) is used as the channel filter.

Fig. 2-7 Measuring the adjacent channel power of a W-CDMA signal with the Fast

ACP method

With W-CDMA, the R&S FSP’s dynamic range for adjacent channel measure­ments is limited by the 12-bit A/D converter. The greatest dynamic range is,
therefore, obtained with the IBW method.

2.42 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Measurements on Modulated Signals

Optimum Level Setting for ACP Measurements on W-CDMA Signals

The dynamic range for ACPR measurements is limited by the thermal noise floor,
the phase noise and the intermodulation (spectral regrowth) of the R&S FSP. The
power values produced by the R&S FSP due to these factors accumulate linearly.
They depend on the applied level at the input mixer. The three factors are shown in
the figure below for the adjacent channel (5 MHz carrier offset)

ACLR / dBc

-30

-35

-40

-45

-50

-55

-60

-65

-70

-75

-80

-40-35-30-25-20-15-10

Phase Noise

Thermal Noise

optimum 10-dB range

Fig. 2.20 The R&S FSP’s dynamic range for adjacent channel power measurements on W-CDMA

uplink signals is a function of the mixer level.

Total ACLR

S.R.I.

Mixer Level / dBm

The level of the W-CDMA signal at the input mixer is shown on the horizontal axis,
i.e. the measured signal level minus the selected RF attenuation. The individual
components which contribute to the power in the adjacent channel and the resulting
relative level (total ACPR) in the adjacent channel are displayed on the vertical axis.
The optimum mixer level is –21 dBm. The relative adjacent channel power (ACPR)
at an optimum mixer level is –65 dBc. Since, at a given signal level, the mixer level
is set in 10 dB steps with the 10 dB RF attenuator, the optimum 10 dB range is
shown in the figure: it spreads from -16 dBm to -26 dBm. The obtainable dynamic
range in this range is 62 dB.

To set the attenuation parameter manually, the following method is recommended:

• Set the RF attenuation so that the mixer level (= measured channel power – RF

attenuation) is between -16 dBm and -26 dBm.

• Set the reference level to the largest possible value where no overload (IFOVLD)

is indicated.

This method is automated with the R&S FSP’s ADJUST REF LEVEL function. Espe­cially in remote control mode, e.g. in production environments, it is best to correctly
set the attenuation parameters prior to the measurement, as the time required for
automatic setting can be saved.

Operating Manual 1164.4556.12 - 06 2.43

R&S FSP Getting Started

Measurements on Modulated Signals

To measure the R&S FSP’s intrinsic dynamic range for W-CDMA adjacent chan­nel power measurements, a filter which suppresses the adjacent channel power
is required at the output of the transmitter. A SAW filter with a bandwidth of 4
MHz, for example, can be used.

2.5.4 Amplitude distribution measurements

If modulation types that do not have a constant envelope in the time domain are
used, the transmitter has to handle peak amplitudes that are greater than the aver­age power. This includes all modulation types that involve amplitude modulation,
QPSK for example. CDMA transmission modes in particular may have power peaks
that are large compared to the average power.

For signals of this kind, the transmitter must provide large reserves for the peak
power to prevent signal compression and thus an increase of the bit error rate at the
receiver.

The peak power, or the crest factor of a signal is therefore an important transmitter
design criterion. The crest factor is defined as the peak power / mean power ratio or,
logarithmically, as the peak level minus the average level of the signal.

To reduce power consumption and cut costs, transmitters are not designed for the
largest power that could ever occur, but for a power that has a specified probability
of being exceeded (e.g. 0.01%).

To measure the amplitude distribution, the R&S FSP has simple measurement func­tions to determine both the APD = Amplitude Probability Distribution and CCDF =
Complementary Cumulative Distribution Function.

In the literature, APD is also used for the probability of amplitude violation. This is
the complimentary function to the APD function of R&S FSP. The term PDF
(=Probability Density Function) which is frequently used in the literature corre­sponds to the APD function of R&S FSP.

In the APD display mode, the probability of occurrence of a certain level is plotted
against the level.

In the CCDF display mode, the probability that the mean signal power will be
exceeded is shown in percent.

2.5.4.1 Measurement Example – Measuring the APD and CCDF of white noise gener­ated by the R&S FSP

1. Set the R&S FSP to its default state.

➢ Press the PRESET key.

The R&S FSP is in its default state.

2. Configure the R&S FSP for APD measurement

➢ Press the AMPT key and enter -60 dBm.

The R&S FSP’s intrinsic noise is displayed at the top of the screen.

➢ Press the MEAS key.
➢ Press the SIGNAL STATISTIC ! softkey.

2.44 Operating Manual 1164.4556.12 - 06

R&S FSP Getting Started

Measurements on Modulated Signals

➢ Set the APD softkey to ON.

The R&S FSP sets the frequency span to 0 Hz and measures the amplitude
probability distribution (APD). The number of uncorrelated level
measurements used for the measurement is 100000. The mean power and the
peak power are displayed in dBm. The crest factor (peak power – mean power)
is output as well (see Fig. 2-1).

Fig. 2-1 Amplitude probability distribution of white noise

3. Switch to the CCDF display mode.

➢ Set the CCDF softkey to ON

The APD measurement is switched off and the CCDF display mode is switched
on.

Fig. 2-2 The CCDF of white noise

The CCDF trace indicates the probability that a level will exceed the mean
power. The level above the mean power is plotted along the X axis of the
graph.The origin of the axis corresponds to the mean power level. The
probability that a level will be exceeded is plotted along the Y axis.

Operating Manual 1164.4556.12 - 06 2.45

R&S FSP Getting Started

Measurements on Modulated Signals

4. Bandwidth selection

If the amplitude distribution is measured, the resolution bandwidth must be set in
a way that the complete spectrum of the signal to be measured falls within the
bandwidth. This is the only way of ensuring that all the amplitudes will pass
through the IF filter without being distorted. If the selected resolution bandwidth is
too small for a digitally modulated signal, the amplitude distribution at the output
of the IF filter becomes a Gaussian distribution according to the central limit
theorem and so corresponds to a white noise signal. The true amplitude
distribution of the signal therefore cannot be determined.

A video bandwidth which is large in comparison to the resolution bandwidth (≥ 3 x
RBW) must be selected. This ensures that the amplitude peaks of the signal are
not smoothed by the lowpass effect of the video filter. The video bandwidth is set
automatically during statistics measurements.

Since the video bandwidth of the R&S FSP is limited to 10 MHz, lowpass filtering
occurs during measurements with a resolution bandwidth of 10 MHz. Additional
band-limiting occurs at a resolution bandwidth of 10 MHz due to the lowpass
filtering at the output of the log amplifier. The latter limits the video signal to a
bandwidth of 8 MHz in order to obtain sufficient suppression of the 20.4 MHz IF.
The level range of the signal amplitudes, e.g. during APD white-noise
measurements, is smaller. For broadband-modulated signals such as W-CDMA
signals, the effect depends on the bandwidth occupied by the signal. At a signal
bandwidth of 4 MHz, the amplitude distribution can be measured correctly with the
effective video bandwidth.

5. Selecting the number of samples

For statistics measurements with the R&S FSP, the number of samples N
is entered for statistical evaluation instead of the sweep time. Since only
statistically independent samples contribute to statistics, the measurement or
sweep time is calculated automatically. It is indicated on the R&S FSP display.
The samples are statistically independent if the time difference is at least 1/RBW.
The sweep time SWT is, therefore, expressed as follows:

SWT = N

Samples

/RBW

Samples

2.46 Operating Manual 1164.4556.12 - 06

R&S FSP Manual Operation

3 Manual Operation

For details refer to the Quick Start Guide chapter 4, “Basic Operation”.

Operating Manual 1164.4556.12 - 06 3.1

R&S FSP Manual Operation

3.2 Operating Manual 1164.4556.12 - 06

R&S FSP Instrument Functions

4 Instrument Functions

4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4

4.2 R&S FSP Initial Configuration – PRESET Key . . . . . . . . . . . . . . . . . . . . . . 4.5

4.3 Mode Selection – Hotkey Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7

4.4 Return to Manual Operation – LOCAL Menu . . . . . . . . . . . . . . . . . . . . . . . 4.8

4.5 Analyzer Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.9

4.5.1 Frequency and Span Selection – FREQ Key . . . . . . . . . . . . . . . . . . . . . 4.9

4.5.2 Setting the Frequency Span – SPAN Key . . . . . . . . . . . . . . . . . . . . . . . 4.13

4.5.3 Level Display Setting and RF Input Configuration – AMPT Key . . . . . . 4.14

4.5.3.1Electronic Attenuator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.17

4.5.4 Setting the Bandwidths and Sweep Time – BW Key . . . . . . . . . . . . . . . 4.18

4.5.4.1Filter Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.24

4.5.4.2List of Available Channel Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.25

4.5.5 Sweep Settings – SWEEP Key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.27

4.5.6 Triggering the Sweep – TRIG Key . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.29

4.5.7 Selection and Setting of Traces – TRACE Key . . . . . . . . . . . . . . . . . . . 4.37

4.5.8 Selection of Trace Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.37

4.5.8.1Selection of Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.44

4.5.8.2Mathematical Functions for Traces . . . . . . . . . . . . . . . . . . . . . . . . 4.48

4.5.9 Recording the Correction Data – CAL Key . . . . . . . . . . . . . . . . . . . . . . 4.49

4.5.10 Markers and Delta Markers – MKR Key . . . . . . . . . . . . . . . . . . . . . . . 4.51

4.5.10.1Frequency Measurement with the Frequency Counter . . . . . . . . 4.53

4.5.11 Marker Functions – MKR FCTN Key . . . . . . . . . . . . . . . . . . . . . . . . . . 4.58

4.5.11.1Activating the Markers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.59

4.5.11.2Measurement of Noise Density . . . . . . . . . . . . . . . . . . . . . . . . . . 4.60

4.5.11.3Phase Noise Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.61

4.5.11.4Measurement of the Filter or Signal Bandwidth . . . . . . . . . . . . . . 4.64

4.5.11.5Measurement of a Peak List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.64

4.5.11.6AF Demodulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.66

4.5.11.7Selecting the Trace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.67

4.5.12 Change of Settings via Markers – MKR-> Key . . . . . . . . . . . . . . . . . . 4.68

Operating Manual 1164.4556.12 - 06 4.1

R&S FSP Instrument Functions

4.5.13 Power Measurements – MEAS Key . . . . . . . . . . . . . . . . . . . . . . . . . . 4.75

4.5.13.1Power Measurement in Time Domain . . . . . . . . . . . . . . . . . . . . . 4.76

4.5.13.2Channel and Adjacent-Channel Power Measurements . . . . . . . . 4.81

4.5.13.3Setting the Channel Configuration . . . . . . . . . . . . . . . . . . . . . . . . 4.91

4.5.13.4Measurement of Signal Amplitude Statistics . . . . . . . . . . . . . . . 4.106

4.5.13.5Measurement of Carrier/Noise Ratio C/N and C/No . . . . . . . . . 4.114

4.5.13.6Measurement of the AM Modulation Depth . . . . . . . . . . . . . . . . 4.116

4.5.13.7Measurement of the Third Order Intercept (TOI) . . . . . . . . . . . . 4.117

4.5.13.8Harmonic Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.120

4.5.13.9Measuring Spurious Emissions . . . . . . . . . . . . . . . . . . . . . . . . . 4.122

4.5.13.10Spectrum Emission Mask Measurement . . . . . . . . . . . . . . . . . 4.129

4.6 Basic Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.146

4.6.1 Setup of Limit Lines and Display Lines – LINES Key . . . . . . . . . . . . . 4.146

4.6.1.1Selection of Limit Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.147

4.6.1.2Entry and Editing of Limit Lines . . . . . . . . . . . . . . . . . . . . . . . . . . 4.151

4.6.1.3Display Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.155

4.6.2 Configuration of Screen Display – DISP Key . . . . . . . . . . . . . . . . . . . 4.157

4.6.3 Instrument Setup and Interface Configuration – SETUP Key . . . . . . . 4.163

4.6.3.1External Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.165

4.6.3.2External Noise Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.167

4.6.3.3RF Preamplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.167

4.6.3.4Transducer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.167

4.6.3.5Programming the Interface Configuration and Time Setup . . . . . 4.172

4.6.3.6System Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.186

4.6.3.7Service Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.188

4.6.3.8Firmware Update . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.192

4.6.4 Saving and Recalling Data Sets – FILE Key . . . . . . . . . . . . . . . . . . . . 4.193

4.6.4.1Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.193

4.6.4.2Operating Concept of File Managers . . . . . . . . . . . . . . . . . . . . . . 4.198

4.6.5 Measurement Documentation – HCOPY Key . . . . . . . . . . . . . . . . . . . 4.202

4.6.5.1Selecting Printer Colors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.205

4.7 TV and RF Trigger – Option R&S FSP-B6 . . . . . . . . . . . . . . . . . . . . . . . . 4.209

4.8 Tracking Generator – Option R&S FSP-B9 . . . . . . . . . . . . . . . . . . . . . . . 4.212

4.8.1 Tracking Generator Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.212

4.8.2 Transmission Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.214

4.8.2.1Calibration of Transmission Measurement . . . . . . . . . . . . . . . . . . 4.214

4.8.2.2Normalization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.216

4.8.3 Reflection Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.219

4.8.3.1Calibration of Reflection Measurement . . . . . . . . . . . . . . . . . . . . 4.220

4.8.4 Calibration Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.220

4.8.5 Frequency-Converting Measurements . . . . . . . . . . . . . . . . . . . . . . . . 4.222

4.8.6 External Modulation of the Tracking Generator . . . . . . . . . . . . . . . . . . 4.223

4.2 Operating Manual 1164.4556.12 - 06

R&S FSP Instrument Functions

4.8.7 Power Offset of the Tracking Generator . . . . . . . . . . . . . . . . . . . . . . . 4.225

4.9 External Generator Control – Option R&S FSP-B10 . . . . . . . . . . . . . . . 4.226

4.9.1 External Generator Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.227

4.9.2 Transmission Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.228

4.9.2.1Calibration of Transmission Measurement . . . . . . . . . . . . . . . . . . 4.228

4.9.2.2Normalization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.230

4.9.3 Reflection Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.233

4.9.3.1Calibration of Reflection Measurement . . . . . . . . . . . . . . . . . . . . 4.234

4.9.4 Calibration Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.234

4.9.5 Frequency-Converting Measurements . . . . . . . . . . . . . . . . . . . . . . . . 4.236

4.9.6 Configuration of an External Generator . . . . . . . . . . . . . . . . . . . . . . . . 4.237

4.9.7 List of Generator Types Supported by the R&S FSP . . . . . . . . . . . . . 4.240

4.10 LAN Interface - Option R&S FSP-B16 . . . . . . . . . . . . . . . . . . . . . . . . . . 4.245

4.10.1 NOVELL Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.245

4.10.2 MICROSOFT Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.245

4.10.3 Remote Data Transfer with TCP/IP Services . . . . . . . . . . . . . . . . . . 4.245

4.11 RSIB Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.247

4.11.1 Remote Control via RSIB Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . 4.247

4.11.1.1Windows Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.247

4.11.1.2UNIX Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.248

4.12 RSIB Interface Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.249

4.12.1 Overview of Interface Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.249

4.12.1.1Variables ibsta, iberr, ibcntl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.250

4.12.1.2Description of Interface Functions . . . . . . . . . . . . . . . . . . . . . . . 4.251

4.12.2 Programming via the RSIB Protocol . . . . . . . . . . . . . . . . . . . . . . . . . 4.258

4.12.2.1Visual Basic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.258

4.12.2.2Visual Basic for Applications (Winword and Excel) . . . . . . . . . . 4.261

4.12.2.3C / C++ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.262

4.13 LO/IF ports for external mixers - Option R&S FSP-B21 . . . . . . . . . . . . 4.265

4.13.1 Connecting an External Mixer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.265

4.13.2 Manual Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.266

4.13.3 Conversion Loss Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.271

4.13.3.1Editing a Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.274

4.13.4 Signal Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.277

4.13.4.1Remarks Concerning Signal Identification with AUTO ID . . . . . 4.278

4.13.5 Introductory Example of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 4.283

4.14 Trigger Port – Option R&S FSP-B28 . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.288

Operating Manual 1164.4556.12 - 06 4.3

R&S FSP Instrument Functions

Introduction

4.1 Introduction

All functions of the R&S FSP and their application are explained in detail in this
chapter. The sequence of the described menu groups depends on the procedure
selected for the configuration and start of a measurement:

1. Resetting the instrument

– “R&S FSP Initial Configuration – PRESET Key” on page 4.5

2. Setting the mode

– “Mode Selection – Hotkey Bar” on page 4.7

– “Return to Manual Operation – LOCAL Menu” on page 4.8

3. Setting the measurement parameters in analyzer mode

– “Analyzer Mode” on page 4.9

4. Basic functions for general settings, printout and data management

– “Setup of Limit Lines and Display Lines – LINES Key” on page 4.146

– “Configuration of Screen Display – DISP Key” on page 4.157

– “Instrument Setup and Interface Configuration – SETUP Key” on page 4.163

– “Saving and Recalling Data Sets – FILE Key” on page 4.193

– “Measurement Documentation – HCOPY Key” on page 4.202

5. Additional and optional functions

– “Tracking Generator – Option R&S FSP-B9” on page 4.212

– “External Generator Control – Option R&S FSP-B10” on page 4.226

– “LAN Interface - Option R&S FSP-B16” on page 4.245

– “LO/IF ports for external mixers - Option R&S FSP-B21” on page 4.265

– “An essential performance criterion to be met by automatic test systems is to

minimize the time overhead of the entire test relative to the net measurement
time. A typical test comprises the following steps:” on page 4.288

The operating concept is described in the Quick Start Guide, chapter 4, “Basic Oper­ation”.

The remote commands (if any) are indicated for each softkey. A detailed description
of the associated remote commands is given in chapter “Remote Control – Descrip-

tion of Commands”.

4.4 Operating Manual 1164.4556.12 - 06

R&S FSP Instrument Functions

R&S FSP Initial Configuration – PRESET Key

4.2 R&S FSP Initial Configuration – PRESET Key

PRESET

Using the PRESET key, the R&S FSP can be set to a predefined initial state.

The settings are selected in a way that the RF input is always protected against
overload, provided that the applied signal levels are in the allowed range for the
instrument.

The initial instrument state set by the PRESET key can be adapted to arbitrary
applications using the STARTUP RECALL function. With this function the STAR­TUP RECALL data set is loaded upon pressing the PRESET key. For further infor­mation refer to section “Saving and Recalling Data Sets – FILE Key” on

page 4.193.

Pressing the PRESET key causes the R&S FSP to enter its initial state according to
the following table:

Operating Manual 1164.4556.12 - 06 4.5

R&S FSP Instrument Functions

R&S FSP Initial Configuration – PRESET Key

Table 4-1 Initial State of R&S FSP

Parameter Settings

Mode Spectrum

Center frequency 1,5 GHz / 3,5 GHz / 6,8 GHz / 15 GHz / 20 GHz

(R&S FSP-3/-7/-13/-30/-40)

Center frequency step size 0.1 * center frequency

Span 3 GHz / 7 GHz / 13,6 GHz / 30 GHz / 40 GHz

(R&S FSP-3/-7/-13/-30/-40)

RF attenuation auto (10 dB)

Reference level -20 dBm

Level range 100 dB log

Level unit dBm

Sweep time auto

Resolution bandwidth auto (3 MHz)

Video bandwidth auto (10 MHz)

FFT filters off

Span / RBW 50

RBW / VBW 0,33

Sweep cont

Trigger free run

Trace 1 clr write

Trace 2/3 blank

Detector auto peak

Trace math off

Frequency offset 0 Hz

Reference level offset 0 dB

Reference level position 100 %

Grid abs

Cal correction on

Noise source off

Input RF

Display Full screen, active screen A

4.6 Operating Manual 1164.4556.12 - 06

R&S FSP Instrument Functions

Mode Selection – Hotkey Bar

4.3 Mode Selection – Hotkey Bar

For fast mode selection the R&S FSP has keys located under the measurement
screen, the so-called hotkeys. These hotkeys are displayed depending on the
options installed on the instrument. According to the selected mode, the correspond­ing softkey menus are displayed (on the right side of the measurement screen).

In this section, only the hotkeys provided by the basic model are described. For
information on the other hotkeys refer to the corresponding option descriptions.

Fig. 4.1 Hotkey bar of the basic model

SPECTRUM

MORE

SCREEN A /
SCREEN B

The SPECTRUM hotkey sets R&S FSP to analyzer mode. For details on the softkey
menus refer to section “Analyzer Mode” on page 4.9.

The analyzer mode is the default mode of R&S FSP.

Remote command: INST:SEL SAN

INST:NSEL 1

The MORE hotkey switches to side hotkey bar(s) and back to the main hotkey bar.
In the side hotkey bar(s), the hotkeys for the options are located. For further infor­mation refer to the descriptions of the corresponding options.

With the SCREEN A / SCREEN B hotkey two different settings can be selected on
the R&S FSP in the FULL SCREEN display mode.

In the SPLIT SCREEN display mode the key switches between active diagram A
and B.

The key designation indicates the diagram which has been activated by means of
the key.

The currently active window is marked by or on the right of the dia­gram.

A

B

Remote command: DISP:WIND<1|2>:SEL A

Operating Manual 1164.4556.12 - 06 4.7

R&S FSP Instrument Functions

Return to Manual Operation – LOCAL Menu

4.4 Return to Manual Operation – LOCAL Menu

LOCAL

The LOCAL menu is displayed on switching the instrument to remote control mode.

At the same time, the hotkey bar is blanked out and all keys are disabled except the
PRESET key.

The LOCAL softkey and the DISPLAY UPDATE ON/OFF softkey are displayed.

Depending on the setting of the DISPLAY UPDATE ON/OFF softkey, the diagrams,
traces and diplay fields are displayed or hidden. For further details on the DISPLAY
UPDATE ON/OFF softkey refer to Instrument Setup and Interface Configuration –

SETUP Key.

The LOCAL key switches the instrument from remote to manual operation, with the
assumption that the remote controller has not previously set the LOCAL LOCKOUT
function.

A change in the control mode consists of:

• Enabling the Front Panel Keys

Returning to manual operation enables all inactive keys and turns on the hotkey
bar. The softkey menu which is displayed is the main menu of the current mode.

• Inserting the measurement diagrams

The blanked diagrams, traces and display fields are inserted.

• Generating the message OPERATION COMPLETE

If, at the time of pressing the LOCAL softkey, the synchronization mechanism via
*OPC, *OPC? or *WAI is active, the currently running measurement procedure is
aborted and synchronization is achieved by setting the corresponding bits in the
registers of the status reporting system.

• Setting Bit 6 (User Request) of the Event Status Register

With a corresponding configuration of the status reporting system, this bit
immediately causes the generation of a service request (SRQ) which is used to
inform the control software that the user wishes to return to front-panel control.
This information can be used, e.g., to interrupt the control program so that the user
can make necessary manual corrections to instrument settings. This bit is set
each time the LOCAL softkey is pressed.

If the LOCAL LOCKOUT function is active in the remote control mode, the front­panel PRESET key is also disabled. The LOCAL LOCKOUT state is left as soon
as the process controller de-activates the REN line or the GPIB cable is discon­nected from the instrument.

4.8 Operating Manual 1164.4556.12 - 06

R&S FSP Instrument Functions

Analyzer Mode

4.5 Analyzer Mode

The analyzer mode is activated by pressing the SPECTRUM hotkey (see also sec­tion “Mode Selection – Hotkey Bar” on page 4.7)

SPECTRUM

4.5.1 Frequency and Span Selection – FREQ Key

The SPECTRUM hotkey selects the mode for spectrum analysis, the so-called ana­lyzer mode.

This mode is the default mode of the R&S FSP.

The functions provided correspond to those of a conventional spectrum analyzer.
The R&S FSP measures the frequency spectrum of the test signal over the selected
frequency range with the selected resolution and sweep time, or, for a fixed fre­quency, displays the waveform of the video signal.

If two displays (screen A and screen B) are opened after switch-on of signal analy­sis, the analyzer mode is only set for the display activated for entry (marked at the
top right corner of diagram). For the other display, the previous settings remain
valid.

Data acquisition and display of measured values is sequential: first in the upper
and then in the lower display.

The FREQ key is used to specify the frequency axis of the active display window.
The frequency axis can be defined either by the start and stop frequency or by the
center frequency and bwthe span (SPAN key). With two windows (SPLIT SCREEN)
displayed at the same time, the input data always refer to the window selected in the
SYSTEM - DISPLAY menu.

FREQ

The softkeys in the CF STEPSIZE menu depend on the selected domain: frequency
domain or time domain.

CENTER

CF STEPSIZE ! 0.1 * SPAN / 0.1 * RBW

0.5 * SPAN / 0.5 * RBW

X * SPAN / X * RBW

= CENTER

= MARKER

MANUAL

START

STOP

FREQUENCY OFFSET

SIGNAL TRACK

! TRACK (ON OFF)

TRACK BW

TRACK THRESHOLD

SELECT TRACE

Operating Manual 1164.4556.12 - 06 4.9

R&S FSP Instrument Functions

Analyzer Mode

EXTERNAL MIXER

(option B21)

CENTER The CENTER softkey opens the window for manually entering the center frequency.

The allowed range of values for the center frequency is:

• for the frequency domain (span >0):

minspan / 2 ≤ f

center

≤ f

max

– minspan / 2

• and for the time domain (span = 0):

0 Hz ≤ f

f

center frequency

center

minspan smallest selectable span > 0 Hz (10 Hz)

max. frequency

f

max

center

≤ f

max

Remote command: FREQ:CENT 100MHz

CF STEPSIZE

The CF STEPSIZE softkey opens a submenu for setting the step size of the center
frequency. The step size can be coupled to the span (frequency domain) or the res­olution bandwidth (time domain) or it can be manually set to a fixed value. The soft­keys are mutually exclusive selection keys.

The softkeys are presented according to the selected domain (frequency or time).

Softkeys in frequency domain:

0.1 * SPAN The 0.1 * SPAN softkey sets the step size for the center frequency entry to 10% of
the span.

Remote command: FREQ:CENT:STEP:LINK SPAN

FREQ:CENT:STEP:LINK:FACT 10PCT

0.5 * SPAN The 0.5 * SPAN softkey sets the step size for the center frequency entry to 50% of
the span.

Remote command: FREQ:CENT:STEP:LINK SPAN

FREQ:CENT:STEP:LINK:FACT 50PCT

X * SPAN The X * SPAN softkey allows the factor defining the center frequency step size to be

entered as % of the span.

Remote command: FREQ:CENT:STEP:LINK SPAN

FREQ:CENT:STEP:LINK:FACT 20PCT

= CENTER The = CENTER softkey sets the step size coupling to MANUAL and the step size to

the value of the center frequency. This function is especially useful during measure­ments of the signal harmonic content because by entering the center frequency
each stroke of the STEP key selects the center frequency of another harmonic.

Remote command: --

4.10 Operating Manual 1164.4556.12 - 06

R&S FSP Instrument Functions

Analyzer Mode

= MARKER The = MARKER softkey sets the step size coupling to MANUAL and the step size to

the value of the marker. This function is especially useful during measurements of
the signal harmonic content at the marker position because by entering the center
frequency each stroke of the STEP key selects the center frequency of another har­monic.

Remote command: --

MANUAL The MANUAL softkey activates the window for entering a fixed step size.

Remote command: FREQ:CENT:STEP 120MHz

Softkeys in time domain:

0.1 * RBW The 0.1 * RBW softkey sets the step size for the center frequency entry to 10% of
the resolution bandwidth.

AUTO 0.1 * RBW corresponds to the default setting.

Remote command: FREQ:CENT:STEP:LINK RBW

FREQ:CENT:STEP:LINK:FACT 10PCT

0.5 * RBW The 0.5 * RBW softkey sets the step size for the center frequency entry to 50% of
the resolution bandwidth.

Remote command: FREQ:CENT:STEP:LINK RBW

FREQ:CENT:STEP:LINK:FACT 50PCT

X * RBW The X * RBW softkey allows the factor defining the center frequency step size to be

entered as % of the resolution bandwidth.

Values between 1 and 100% in steps of 1% are allowed. The default setting is 10%.

Remote command: FREQ:CENT:STEP:LINK RBW

FREQ:CENT:STEP:LINK:FACT 20PCT

= CENTER The = CENTER softkey sets the step size coupling to MANUAL and the step size to

the value of the center frequency. This function is especially useful during measure­ments of the signal harmonic content because by entering the center frequency
each stroke of the STEP key selects the center frequency of another harmonic.

Remote command: --

= MARKER The = MARKER softkey sets the step size coupling to MANUAL and the step size to

the value of the marker. This function is especially useful during measurements of
the signal harmonic content at the marker position because by entering the center
frequency each stroke of the STEP key selects the center frequency of another har­monic.

Remote command: --

MANUAL The MANUAL softkey activates the window for entering a fixed step size.

Remote command: FREQ:CENT:STEP 120MHz

Operating Manual 1164.4556.12 - 06 4.11

R&S FSP Instrument Functions

Analyzer Mode

START

STOP

FREQUENCY
OFFSET

The START softkey activates the window for manually entering the start frequency.

The allowed range of values for the start frequency is:
0 Hz ≤ f

f

start frequency

start

minspan smallest selectable span (10 Hz)

max. frequency

f

max

start

≤ f

- minspan

max

Remote command: FREQ:STAR 20MHz

The STOP softkey activates the window for entering the stop frequency.

The allowed range of values for the stop frequency is:
minspan ≤ f

f

stop frequency

stop

minspan smallest selectable span (10 Hz)

max. frequency

f

max

stop

≤ f

max

Remote command: FREQ:STOP 2000MHz

The FREQUENCY OFFSET softkey activates the window for entering an arithmeti­cal frequency offset which is added to the frequency axis labelling. The allowed
range of values for the offset is -100 GHz to 100 GHz. The default setting is 0 Hz.

SIGNAL
TRACK

Remote command: FREQ:OFFS 10 MHz

The SIGNAL TRACK softkey switches on the tracking of a signal near the center fre­quency. The signal is tracked as long it is in the search bandwidth around the center
frequency defined with TRACK BW and above the level threshold defined with
TRACK THRESHOLD.

For that purpose, the maximum signal is searched (PEAK SEARCH) on the screen
and the center frequency set to this signal (MARKER ->CENTER) after each fre­quency sweep within the search bandwidth.

If the signal falls below the level threshold or jumps out of the search bandwidth
around the center frequency, the center frequency is not varied until a signal is in the
search bandwidth above the level threshold. This can be achieved by manually
modifying the center frequency, for example.

On switching on, the softkey is highlighted and the search bandwidth and the thresh­old value are marked on the diagram by two vertical lines and one horizontal line. All
these lines are provided with the designation TRK.

At the same time a submenu is opened in which the search bandwidth, the threshold
value and the trace can be modified for the maximum search.

The softkey is only available in the frequency domain (span >0).

Remote command: CALC:MARK:FUNC:STR OFF

TRACK (ON

The TRACK (ON OFF) softkey switches on and off signal tracking.

OFF)

Remote command: CALC:MARK:FUNC:STR OFF

4.12 Operating Manual 1164.4556.12 - 06

R&S FSP Instrument Functions

Analyzer Mode

TRACK BW The TRACK BW softkey defines the search bandwidth for signal tracking. The fre-

quency range is symmetrical with respect to the center frequency.

Remote command: CALC:MARK:FUNC:STR:BAND 10KHZ

TRACK

THRESHOLD

The TRACK THRESHOLD softkey defines the threshold value for signal detection.
The value is always entered as an absolute level value.

Remote command: CALC:MARK:FUNC:STR:THR -70DBM

SELECT TRACE The SELECT TRACE softkey selects the trace on which signal tracking is to be per-

formed.

Remote command: CALC:MARK:FUNC:STR:TRAC 1

4.5.2 Setting the Frequency Span – SPAN Key

The SPAN key opens a menu which offers various options for setting the span.

The entry of the span (SPAN MANUAL softkey) is automatically active for span > 0
Hz.

For span = 0 Hz the entry for sweep time (SWEEPTIME MANUAL) is automatically
active.

With two windows (SPLIT SCREEN) displayed at the same time, the input data
always refer to the window selected with the SCREEN A/B hotkey.

SPAN

SPAN MANUAL

SWEEPTIME MANUAL

SPAN
MANUAL

SWEEPTIME
MANUAL

FULL SPAN

ZERO SPAN

LAST SPAN

FREQ AXIS (LIN LOG)

The SPAN MANUAL softkey activates the window for manually entering the fre­quency span. The center frequency is kept constant.

Allowed range of span values:

• for the time domain (span = 0): 0 Hz

• and for the frequency domain (span >0): minspan ≤ f

f

frequency span

span

minspan smallest selectable span (10 Hz)

max. frequency

f

max

span

≤ f

max

Remote command: FREQ:SPAN 2GHz

The SWEEPTIME MANUAL softkey activates the window for entering the sweep
time manually with Span = 0 Hz. The softkey is not available for Span > 0 Hz.

Remote command: SWE:TIME 10s

Operating Manual 1164.4556.12 - 06 4.13

R&S FSP Instrument Functions

Analyzer Mode

FULL SPAN

ZERO SPAN

LAST SPAN

FREQ AXIS
(LIN LOG)

The FULL SPAN softkey sets the span to the full frequency range of R&S FSP.

Remote command: FREQ:SPAN:FULL

The ZERO SPAN softkey sets the span to 0 Hz. The x-axis becomes the time axis
with the grid lines corresponding to 1/10 of the current sweep time (SWT).

Remote command: FREQ:SPAN 0Hz

After changing the span setting the LAST SPAN softkey activates the previous set-
ting. With this function a fast change between overview measurement (FULL SPAN)
and detailed measurement (manually set center frequency and span) is possible.

Only values > 0 Hz are restored, i.e. a transition between time and frequency
domain is not possible.

Remote command: --

The FREQ AXIS (LIN LOG) softkey switches between linear and logarithmic scaling
of the frequency axis. Switch over is only possible if the stop/start frequency ratio is
≥1.4.

The default state is LIN.

AMPT

The logarithmic frequency axis is only available in analyzer mode and it is not avail­able in zero span mode, in external mixer mode, with frequency offset or if the ratio
stop frequency / start frequency is below 1.4.

Remote command: DISP:WIND<1|2>:TRAC:X:SPAC LIN

4.5.3 Level Display Setting and RF Input Configuration – AMPT Key

The AMPT key is used to set the reference level, the maximum level and the display
range of the active window as well as the input impedance and the input attenuation
of the RF input.

The AMPT key opens a menu for setting the reference level and the input attenua­tion of the active window. The data entry for the reference level (REF LEVEL soft­key) is opened automatically.

Further settings regarding level display and attenuation can be made in this menu.

REF LEVEL

RANGE LOG 100 dB

RANGE LOG MANUAL

RANGE LINEAR

! RANGE LINEAR %

RANGE LINEAR dB

UNIT

! dBm / dBmV / dBµV/

dBµΑ / dBµW / VOLT /
AMPERE / WATT

RF ATTEN MANUAL

4.14 Operating Manual 1164.4556.12 - 06

R&S FSP Instrument Functions

Analyzer Mode

RF ATTEN AUTO

MIXER

! MIXER LOW NOISE

Side menu

REF LEVEL POSITION

REF LEVEL OFFSET

GRID (ABS REL)

EL ATTEN AUTO (option B25)

EL ATTEN MANUAL (option B25)

EL ATTEN OFF (option B25)

RF INPUT (50W 75W)

REF LEVEL

RANGE LOG
100 dB

RANGE LOG
MANUAL

RANGE
LINEAR

The REF LEVEL softkey allows the reference level to be input in the currently active
unit (dBm, dBµV, etc.)

Remote command: DISP:WIND:TRAC:Y:RLEV -60dBm

The RANGE LOG 100 dB softkey sets the level display range to 100 dB.

Remote command: DISP:WIND:TRAC:Y:SPAC LOG

DISP:WIND:TRAC:Y 100DB

The RANGE LOG MANUAL softkey activates the manual entry of the level display
range. Display ranges from 1 to 200 dB are allowed in 10 dB steps. Inputs which are
not allowed are rounded to the next valid value.

The default setting is 100 dB.

Remote command: DISP:WIND:TRAC:Y:SPAC LOG

DISP:WIND:TRAC:Y 120DB

The RANGE LINEAR softkey selects linear scaling for the level display range of the
R&S FSPr. In addition, it opens a submenu for selecting % or dB for the scaling.

When linear scaling is selected, the % scaling is first activated (see also RANGE
LINEAR dB softkey).

Remote command: DISP:WIND:TRAC:Y:SPAC LIN

RANGE

LINEAR %

The RANGE LINEAR % softkey selects linear scaling in % for the level display
range, i.e. the horizontal lines are labelled in %. The grid is divided in decadic steps.
Markers are displayed in the selected unit; delta markers are displayed in % refer­enced to the voltage value at the position of marker 1.

Remote command: DISP:WIND:TRAC:Y:SPAC LIN

RANGE

LINEAR dB

The RANGE LINEAR dB softkey selects linear scaling in dB for the level display
range, i.e. the horizontal lines are labelled in dB.

Markers are displayed in the selected unit; delta markers are displayed in dB refer­enced to the power value at the position of marker 1.

Remote command: DISP:WIND:TRAC:Y:SPAC LDB

Operating Manual 1164.4556.12 - 06 4.15

R&S FSP Instrument Functions

Analyzer Mode

UNIT

RF ATTEN
MANUAL

dBm

dBmV

dBµV

dBµΑ

dBµW

VOLT

AMPERE

WATT

The UNIT softkey opens a submenu to select the unit for the level axis.

The default setting is dBm.

In general, the R&S FSP measures the signal voltage at the RF input. The level dis­play is calibrated in rms values of an unmodulated sinewave signal. In the default
state, the level is displayed at a power of 1 mW (= dBm). Via the known input resis­tance of 50 Ω or 75W, conversion to other units is possible. The units dBm, dBmV,
dBµV, dBµA, dBpW, V, A and W are directly convertible.

Remote command: CALC:UNIT:POW DBM

The RF ATTEN MANUAL softkey allows the attenuation to be entered irrespective of
the reference level.

RF ATTEN
AUTO

MIXER

The attenuation can be set in 10 dB steps between 0and 70 dB (in 5 dB steps
between 0 and 75 dB if option B25, Electronic Attenuator, is fitted).

Other entries will be rounded to the next higher integer value.

If the defined reference level cannot be set for the given RF attenuation, the refer­ence level will be adjusted accordingly and the warning "Limit reached" will be out­put.

The 0 dB value can be entered only via the numeric keypad in order to protect the
input mixer against accidental overload.

Remote command: INP:ATT 40 DB

The RF ATTEN AUTO softkey sets the RF attenuation automatically as a function of
the selected reference level.

This ensures that the optimum RF attenuation desired by the user is always used.

RF ATTEN AUTO is the default setting.

Remote command: INP:ATT:AUTO ON

The MIXER softkey opens a submenu for defining the maximum mixer level attain­able for the selected reference level.

4.16 Operating Manual 1164.4556.12 - 06

R&S FSP Instrument Functions

Analyzer Mode

MIXER LOW

NOISE

REF LEVEL
POSITION

REF LEVEL
OFFSET

The MIXER LOW NOISE softkey changes the operating point of the input mixer so
that (with the RF attenuation remaining the same) the inherent noise of the
R&S FSP is reduced compared to the default setup. If the softkey is enabled, the
R&S FSP has an improved dynamic range above 3 GHz.

• The function is available for models 13, 30 and 40.

• The modified operating point of the input mixer will be effective only if the start

frequency of the R&S FSP is ≥3 GHz.

• In the default setting, the function is switched off.

Remote command: INP:ATT:AUTO:MODE LNO

The REF LEVEL POSITION softkey allows the reference level position to be
entered.

The setting range is from -200 to +200%, 0% corresponding to the lower and 100%
to the upper limit of the diagram.

Remote command: DISP:WIND:TRAC:RPOS 100PCT

The REF LEVEL OFFSET softkey allows the arithmetic level offset to be entered.
This offset is added to the measured level irrespective of the selected unit. The scal­ing of the y-axis is changed accordingly.

GRID
(ABS REL)

4.5.3.1 Electronic Attenuator

The setting range is ±200 dB in 0.1 dB steps.

Remote command: DISP:WIND:TRAC:RLEV:OFFS -10dB

Remote command:

The GRID (ABS REL) softkey switches between absolute and relative scaling of the
level axis.

GRID ABS is the default setting.

ABS The labelling of the level lines refers to the absolute value of the reference

level.

REL The upper line of the grid is always at 0 dB.

The scaling is in dB whereas the reference level is always in the set unit
(dBm, dBmV,..).

For setting RANGE LINEAR (linear scaling, labelling of axes in %) the softkey is not
displayed since the unit % itself implies a relative scale.

Remote command: DISP:WIND:TRAC:Y:MODE ABS

Besides the mechanical attenuator at the RF input, the R&S FSP also offers an
electronic attenuation setting (option ELECTRONIC ATTENUATOR R&S FSP-B25).
The attenuation range is 0 to 30 dB, with the default attenuation being preset by the
mechanical attenuator.

EL ATTEN
MANUAL

Operating Manual 1164.4556.12 - 06 4.17

The EL ATTEN MANUAL softkey switches the electronic attenuator on and allows
the attenuation of the electronic attenuator to be set.

R&S FSP Instrument Functions

Analyzer Mode

The attenuation can be varied in 5 dB steps from 0 to 30 dB. Other entries are
rounded to the next lower integer value.

If the defined reference level cannot be set for the given RF attenuation, the refer­ence level will be adjusted accordingly and the warning "Limit reached" will be out­put.

Remote command: INP:EATT:AUTO OFF

INP:EATT 10 DB

This function is only available with option ELECTRONIC ATTENUATOR B25.

EL ATTEN
AUTO

EL ATTEN OFF

RF INPUT

Ω 75Ω)

(50

The EL ATTEN AUTO softkey switches the electronic attenuator on and automati-
cally sets its attenuation to 0 dB.

The allowed setting range of the reference level ranges from the current reference
level on switching on the electronic attenuator to over 30 dB. If a reference level is
set outside the allowed 30-dB range, setting is performed by means of the mechani­cal attenuator. From this new reference level to over 30 dB the setting is again per­formed with the electronic attenuator.

Remote command: INP:EATT:AUTO ON

This function is only available with option ELECTRONIC ATTENUATOR B25.

The EL ATTEN OFF softkey switches the electronic attenuator off.

Remote command: INP:EATT:STAT OFF

This function is only available with option ELECTRONIC ATTENUATOR B25.

The RF INPUT (50 Ω 75 Ω) softkey switches the input impedance of the instrument
between 50 Ω (= default setting) and 75 Ω.

The setting 75 Ω should be used if the input impedance (50 Ω) is transformed to 75
Ω using the corresponding adapter unit of type RAZ (= 25 Ω in series to the input
impedance of the R&S FSP). The correction value used for the adoption is 1.76 dB
= 10 log (75Ω / 50Ω).

All levels specified in this operating manual refer to the default setting of the instru­ment (50 Ω).

Remote command: INP:IMP 50OHM

4.5.4 Setting the Bandwidths and Sweep Time – BW Key

The BW key calls a menu for setting the resolution bandwidth (RBW), video band­width (VBW) and sweep time (SWT) for the frequency sweep. The parameters may
be coupled dependent on the span (stop minus start frequency) or freely set by the
user. When working with a split screen display, the settings always refer to the active
window.

The R&S FSP offers resolution bandwidths from 10 Hz to 10 MHz in 1, 3, 10 steps.

Resolution bandwidths up to 100 kHz are realized using digital bandpasses with
Gaussian characteristics. As far as the attenuation characteristic is concerned they
behave like analog filters but have a much higher measurement speed than compa­rable analog filters. This is due to the fact that the transient response can be com­pensated as a result of an accurately defined filter behavior.

4.18 Operating Manual 1164.4556.12 - 06

R&S FSP Instrument Functions

Analyzer Mode

Bandwidths above 100 kHz are realized using decoupled 4-circuit LC filters.

As an alternative to the analog filters, FFT filters are available for the bandwidths
between 1 Hz and 30 kHz. When working with bandwidths up to 30 kHz, the FFT
algorithm offers considerably higher measurement speeds with all the other settings
remaining the same. The reason is that with analog filters the sweep time required
for a particular span is proportional to (Span/RBW

2

). When using the FFT algorithm,

however, the sweep time is proportional to (Span/RBW).

The video bandwidths are available in 1, 3, 10 steps between 1 Hz and 10 MHz.
They can be set in accordance with the resolution bandwidth.

The video filters serve for smoothing the displayed trace. Video bandwidths that are
small compared to the resolution bandwidth average out noise peaks and pulsed
signals, so that only the signal average is displayed. If pulsed signals are to be mea­sured, it is recommended to use a video bandwidth that is large compared to the
resolution bandwidth (VBW ≥ 10 × RBW) for the amplitudes of pulses to be mea­sured correctly.

For analog and digital filters, the R&S FSP has overload reserves of different mag­nitude above the reference level. Due to the LO breakthrough the overload display
OVLD responds with digital filters with RBW < 100 kHz, as soon as the start fre­quency is selected < 6 × RBW; for RBW = 100 kHz as soon as the start frequency
is below 3 MHz.

BW

RES BW MANUAL

VIDEO BW MANUAL

SWEEPTIME MANUAL

RES BW AUTO

VIDEO BW AUTO

SWEEPTIME AUTO

COUPLING RATIO

DEFAULT COUPLING

FILTER TYPE

Side menu

VBW MODE (LIN LOG)

! RBW / VBW SINE [1/3]

RBW / VBW
PULSE [0.1]

RBW / VBW NOISE [10]

RBW / VBW MANUAL

SPAN / RBW AUTO [50]

SPAN / RBW MANUAL

The BW key opens a menu for setting the resolution bandwidth, the video bandwidth,
the sweep time and their couplings.

The …BW AUTO softkeys are used to couple the functions. The coupling ratios are
selected by means of the COUPLING RATIO softkey.

Operating Manual 1164.4556.12 - 06 4.19

R&S FSP Instrument Functions

Analyzer Mode

The …BW MANUAL softkeys allow a parameter to be entered. This parameter is not
coupled to the other parameters.

With the …BW AUTO softkeys the resolution bandwidth, the video bandwidth and
the sweep time can be entered separately for the frequency domain (span > 0 Hz)
and the time domain (span = 0 Hz).

But with …BW MANUAL softkeys the selected values apply to both the frequency
and time domain.

RES BW
MANUAL

VIDEO BW
MANUAL

The RES BW MANUAL softkey activates the manual data entry for the resolution
bandwidth.

The resolution bandwidth can be selected in 1/3/10 steps in the range between 10
Hz and 10 MHz. The nominal resolution bandwidth is the 3 dB bandwidth.

When FFT filters are used, the lower limit of the bandwidth is 1 Hz. FFT filters may
be used with bandwidths up to 30 kHz.

For numeric inputs, the values are always rounded to the nearest possible band­width. For rotary knob or UP/DOWN key inputs, the bandwidth is adjusted in steps
either upwards or downwards.

For filter type CHANNEL or RRC, the bandwidth is selected from the list of available
channel filters given in section “Filter Types” on page 4.24.

For data entry, the cursor keys Uu and Ud scroll through this list.

The manual input mode of the resolution bandwidth is indicated by a green asterisk
(*) on the display.

Remote command: BAND:AUTO OFF;

BAND 1MHz

The VIDEO BW MANUAL softkey activates the manual data entry for the video
bandwidth.

The video bandwidth can be selected in 1/3/10 steps in the range between 1 Hz and
10 MHz.

For numeric inputs, the values are always rounded to the nearest possible allowed
bandwidth. For rotary knob or UP/DOWN key inputs, the bandwidth is adjusted in
steps either downwards or upwards.

The manual input mode of the video bandwidth is indicated by a green asterisk (*)
on the display.

Remote command: BAND:VID:AUTO OFF;

BAND:VID 10 kHz

SWEEPTIME
MANUAL

4.20 Operating Manual 1164.4556.12 - 06

The SWEEPTIME MANUAL softkey activates the manual data entry for the sweep
time. At the same time, the coupling of the sweep time is cancelled. Other couplings
(VIDEO BW, RES BW) remain effective.

In the frequency domain (span > 0 Hz) and for resolution bandwidths above 1 kHz,
the allowed sweep times for spans > 3.2 kHz range from 2.5 ms through to 16000 s.
With spans below 3.2 kHz, the maximum allowed sweep time is reduced to 5 s *
span/Hz.

If FFT filters are used, the sweep time is fixed by the span and the bandwidth and
therefore cannot be set.

R&S FSP Instrument Functions

Analyzer Mode

In time domain (span = 0 Hz), the range of sweep times is 1 µs to 16000 s is select­able in steps of max. 5% of the sweep time. For numeric inputs, rounding is made to
the nearest possible sweep time. For rotary knob or UP/DOWN key inputs, the
sweep time is adjusted in steps either downwards or upwards.

The manual input mode of the sweep time is indicated by a green asterisk (*) on the
display. If the selected sweep time is too short for the selected bandwidth and span,
level measurement errors will occur. This happens because the available settling
time for the resolution or video filters is too short. In this case, the R&S FSP outputs
UNCAL on the display and marks the indicated sweep time with a red asterisk (*).

Remote command: SWE:TIME:AUTO OFF;

SWE:TIME 10s

RES BW AUTO

VIDEO BW
AUTO

The RES BW AUTO softkey couples the resolution bandwidth to the selected span.
Changing the span causes automatic adjustment of the resolution bandwidth.

Automatic coupling of resolution bandwidth to span is always recommended when a
favorable setting of the resolution bandwidth in relation to the selected span is
desired for the measurement under request.

The coupling ratio is set in the COUPLING RATIO submenu.

The RES BW AUTO softkey is only available in the frequency domain (span > 0 Hz).
The softkey is deactive in the time domain.

Remote command: BAND:AUTO ON

The VIDEO BW AUTO softkey couples the video bandwidth to the resolution band­width. If the resolution bandwidth is changed, the video bandwidth is automatically
adjusted.

The coupling of the video bandwidth is always recommended when the minimum
sweep time is required for a selected resolution bandwidth. Narrower video band­widths require longer sweep times due to the longer settling time. Wider bandwidths
reduce the signal/noise ratio.

The coupling ratio is set in the COUPLING RATIO submenu.

The coupling of the video bandwidth to the resolution filter is also permitted for the
time domain display (span = 0).

Remote command: BAND:VID:AUTO ON

SWEEPTIME
AUTO

Operating Manual 1164.4556.12 - 06 4.21

The SWEEPTIME AUTO softkey couples the sweep time to the span, video band­width (VBW) and resolution bandwidth (RBW). The sweep time is automatically
adjusted on any change in span, resolution bandwidth or video bandwidth.

The softkey is only available in the frequency domain (span >0 Hz). It is blanked in
the time domain.

The R&S FSP always selects the shortest sweep time possible without falsifying the
signal. The maximum level error compared to using a longer sweep time is < 0.1 dB.
If additional bandwidth and level errors are to be avoided, the sweep time is to be
set to three times the time offered in coupled mode.

The frequency scan rates required when using the quasipeak detector are defined in
Annex B in CISPR 16-2-x:

R&S FSP Instrument Functions

Analyzer Mode

Band A Band B Band C/D

Frequency range < 150 kHz 150 kHz to 30 MHz > 30 MHz

IF bandwidth 200 Hz 9 kHz 120 kHz

Frequency scan rate 20 s/kHz 200 s/MHz 20 s/MHz

The SWEEPTIME AUTO function is designed for detectors like sample, max peak or
average. For sweeping with the quasipeak detector a manual setting of the sweep
time should be used at any time.

Remote command: SWE:TIME:AUTO ON

COUPLING
RATIO

The COUPLING RATIO softkey opens a submenu for selection of the coupling ratios.

RBW / VBW SINE [1/3]

RBW / VBW PULSE [0.1]

RBW / VBW NOISE [10]

RBW / VBW MANUAL

SPAN / RBW AUTO [50]

SPAN / RBW MANUAL

When the default setting is active, i.e. the COUPLING RATIO softkey is deactivated
(not highlighted), the ratio span/resolution bandwidth (SPAN/RBW) is 50 (this corre­sponds to SPAN / RBW AUTO [50]) and the ratio resolution bandwidth/video band­width (RBW/VBW) is 0.33 (this corresponds to RBW / VBW SINE [1/3]).

If the ratio RBW/VBW or SPAN/RBW is different from the default setting, the COU-
PLING RATIO softkey is highlighted.

The softkeys RBW/VBW... are selection keys. Only one softkey can be enabled at
any one time. The softkeys are only effective for the VBW AUTO selection in the
main menu.

The softkeys SPAN/RBW... are also selection keys. They are only effective for the
RBW AUTO selection in the main menu.

RBW / VBW

SINE [1/3]

The RBW | VBW SINE [1/3] softkey sets the following coupling ratio:

video bandwidth = 3 × resolution bandwidth.

This is the default setting for the coupling ratio resolution bandwidth/video band­width.

This is the coupling ratio recommended if sinusoidal signals are to be measured.

Remote command: BAND:VID:RAT 3

This setting is only effective for the VBW AUTO selection in the main menu.

RBW / VBW
PULSE [0.1]

The RBW | VBW PULSE [0.1] softkey sets the following coupling ratio:
video bandwidth = 10 × resolution bandwidth or

video bandwidth = 10 MHz (= max. VBW).

4.22 Operating Manual 1164.4556.12 - 06

R&S FSP Instrument Functions

Analyzer Mode

This coupling ratio is recommended whenever the amplitudes of pulsed signals are
to be measured correctly. The IF filter is exclusively responsible for pulse shaping.
No additional evaluation is performed by the video filter.

Remote command: BAND:VID:RAT 10

This setting is only effective for the VBW AUTO selection in the main menu.

RBW / VBW

NOISE [10]

RBW / VBW

MANUAL

SPAN / RBW

AUTO [50]

The RBW/VBW NOISE [10] softkey sets the following coupling ratio:
video bandwidth = resolution bandwidth/10

At this coupling ratio, noise and pulsed signals are suppressed in the video domain.
For noise signals, the average value is displayed.

Remote command: BAND:VID:RAT 0.1

This setting is only effective for the VBW AUTO selection in the main menu.

The RBW/VBW MANUAL softkey activates the manual input of the coupling ratio.

The resolution bandwidth/video bandwidth ratio can be set in the range 0.001 to

1000.

Remote command: BAND:VID:RAT 10

This setting is only effective for the VBW AUTO selection in the main menu.

The SPAN/RBW AUTO [50] softkey sets the following coupling ratio:
resolution bandwidth = span/50

This coupling ratio is the default setting of the R&S FSP

Remote command: BAND:RAT 0.02

This setting is only effective for the RBW AUTO selection in the main menu.

SPAN / RBW

MANUAL

DEFAULT
COUPLING

FILTER TYPE

The SPAN/RBW MANUAL softkey activates the manual input of the coupling ratio.

The span / resolution bandwidth ratio can be set in the range
1 to 10000.

Remote command: BAND:RAT 0.1

This setting is only effective for the RBW AUTO selection in the main menu.

The DEFAULT COUPLING softkey sets all coupled functions to the default state
(AUTO). In addition, the ratio RBW/VBW is set to SINE [1/3] and the ratio SPAN/
RBW to 50 in the COUPLING RATIO submenu (default setting, COUPLING RATIO
softkey not highlighted).

Remote command: BAND:AUTO ON

BAND:VID:AUTO ON
SWE:TIME:AUTO ON

The FILTER TYPE softkey opens the selection list for different filter types. In the
range up to 30 kHz digital band filters with Gaussian characteristic and filtering with
FFT algorithm can be selected.

Operating Manual 1164.4556.12 - 06 4.23

R&S FSP Instrument Functions

Analyzer Mode

4.5.4.1 Filter Types

• NORMAL (3dB): The resolution bandwidths are implemented by Gaussian filters

with the set 3 dB bandwidth and correspond approximately to the noise
bandwidth. For bandwidths up to 100 kHz, digital bandpass filters are used.

• FFT: An FFT is performed. For that purpose, the filtered IF signal is digitized and

then transformed into the spectral domain via FFT. The transformation range
depends on the selected filter bandwidths and can be set between 4 kHz to 50
kHz. If the span is larger than the transformation range, several transformations
are performed and the results are appended to each other in the spectral domain.

If the span is smaller than the transformation range, the measurement results are
interpolated when the number of measurement points provided by the FFT is
smaller than the number of display points in x-direction (625). A flattop window
serves as a window in the time domain so that high amplitude precision with good
selection is achieved.

Compared to bandpasses, FFT filters lead to significantly reduced sweep times.
For a span of 50 kHz and a bandwidth of 100 Hz, for instance, the sweep time is
reduced from 5 s to 40 ms. FFT filters are particularly suitable for stationary
signals (sinusoidal signals or signals that are continuously modulated in time). For
burst signals (TDMA) or pulsed signals, normal filters are preferable.

As soon as the FFT filters are active (RBW ≤ 30 kHz) the sweep time display field
(SWT) is replaced by the acquisition time (AQT) display field.

FFT is a block transformation so the result depends on the time relation between
the data set to be transformed and the burst or pulsed signal. A gated sweep mea­surement for TDMA signals is therefore not provided if FFT filters are used.

When the tracking generator (option R&S FSP-B9) is used as signal source for the
DUT, filtering with the FFT algorithm is not useful. The selection FFT is thus not
available if the tracking generator is switched on.

Additionally, a number of especially steep-edged channel filters are available for
power measurement since firmware version 1.10.

• CHANNEL = general, steep-edged channel filters

• RRC = filters with root-raised cosine characteristic

(RRC = Root Raised Cosine)

When selecting these filter types, the automatic coupling of the resolution bandwidth
to the span is not available. The filters are selected via the RES BW softkey.

A list of all available channel filters with their associated applications can be found at
the end of this section.

Remote command: SENS:BAND:RES:TYPE NORM | FFT | CFIL | RRC

4.24 Operating Manual 1164.4556.12 - 06

R&S FSP Instrument Functions

Analyzer Mode

4.5.4.2 List of Available Channel Filters

The channel filters included in the following table can be activated via the FILTER
TYPE softkey and are then available as resolution filters (softkey RES BW)

They are available for firmware version 1.10 or higher.

For filters of type RRC (Root Raised Cosine), the filter bandwidth indicated
describes the sampling rate of the filter.

For all other filters (CFILter) the filter bandwidth is the 3 dB bandwidth.

Filter Bandwidth Filter Type Application

100 Hz

200 Hz

300 Hz

500 Hz

1 kHz

1.5 kHz

2 kHz

2.4 kHz

2.7 kHz

3 kHz

3.4 kHz

4 kHz

4.5 kHz

5 kHz

6 kHz

7.5 kHz

8.5 kHz

9 kHz

10 kHz

12.5 kHz

14 kHz

15 kHz

16 kHz
18 kHz, α=0.35

20 kHz

21 kHz

24.3 kHz, α=0.35

25 kHz

30 kHz

50 kHz

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

RRC

CFILter

CFILter

RRC

CFILter

CFILter

CFILter

A0

SSB

DAB, Satellite

ETS300 113 (12.5 kHz channels)

AM Radio

CDMAone

ETS300 113 (20 kHz channels)

ETS300 113 (25 kHz channels)

TETRA

PDC

IS 136

CDPD, CDMAone

100 kHz

150 kHz

192 kHz

200 kHz

300 kHz

500 kHz

CFILter

CFILter

CFILter

CFILter

CFILter

CFILter

FM Radio

PHS

J.83 (8-VSB DVB, USA)

Operating Manual 1164.4556.12 - 06 4.25

R&S FSP Instrument Functions

Analyzer Mode

Filter Bandwidth Filter Type Application

VBW MODE
(LIN LOG)

1.0 MHz

1.2288 MHz

1.5 MHz

2.0 MHz *)

3.0 MHz *)

3.84 MHz, a=0.22 *)

4.096 MHz, a=0.22 *)

5.0 MHz *)

5.6 MHz

6 MHz

6.4 MHz

*) This filter is avaible with modification index > 2 of the IF filter module (see softkey SETUP - SYSTEM INFO - HARDWARE INFO).

CFILter

CFILter

CFILter

CFILter

CFILter

RRC

RRC

CFILter

CFILter

CFILter

CFILter

CDMAone

CDMAone

DAB

W-CDMA 3GPP

W-CDMA NTT DOCoMo

DVB-T (Japan)

J.83 (8VSB DVB, USA)

DVB-T

The VBW MODE (LIN LOG) softkey determines the position of the video filter in the
signal path for resolution bandwidths ≤ 100 kHz:

• If LINear is selected, the video filter will be in front of the logarithmic amplifier

(default).

• If LOGarithmic is selected, the video filter will be behind the logarithmic amplifier.

The essential difference between the two operating modes relates to the settling in
case of falling signal edges:

With LINear, the falling signal edge will be "flatter" than with LOGarithmic.

This is due to the conversion from linear power to logarithmic level units: a reduction
of the linear power by 50% reduces the logarithmic signal level by only 3 dB.

This is important for EMI measurements above 1 GHz. Below 1 GHz, CISPR 16-1-1
defines the linear average detector only. Above 1 GHz both, the linear and the loga­rithmic average detector may be specified in product standards. Some standards
(e.g. ANSI C63.4:2000) require the linear average detector, whereas microwave
oven measurements may be made with the log average detector. CISPR 11 speci­fies weighted measurements with a VBW of 10 Hz.

Fig. 4.2 shows the response of the linear and the logarithmic average detector for

pulse-modulated signals.

4.26 Operating Manual 1164.4556.12 - 06

R&S FSP Instrument Functions

Analyzer Mode

SWEEP

Fig. 4.2 Reponses of the linear and the logarithmic average detectors as a function of pulse

repetition frequency (PRF) for pulse-modulated signals with pulse durations of 400 ns
and 1 ms. Resolution bandwidth is 1 MHz.

Remote command: BAND:VID:TYPE LIN

4.5.5 Sweep Settings – SWEEP Key

The SWEEP key serves for configuring the sweep mode and opens the SWEEP
softkey menu. In split-screen mode, the entries made are valid for the active window
only.

The CONTINUOUS SWEEP, SINGLE SWEEP and SGL SWEEP DISP OFF soft-
keys are mutually exclusive selection keys.

CONTINUOUS SWEEP

SINGLE SWEEP

CONTINUE SGL SWEEP

SWEEPTIME MANUAL

SWEEPTIME AUTO

SWEEP COUNT

SWEEP POINTS

SGL SWEEP DISP OFF

CONTINUOUS
SWEEP

The CONTINUOUS SWEEP softkey activates the continuous sweep mode, which
means that the sweep takes place continuously according to the trigger mode set.

When working in the split-screen mode and with different settings in the two win­dows, screen A is swept first, followed by screen B. When the softkey is pressed,
the sweep is restarted.

CONTINUOUS SWEEP is the default setting of R&S FSP.

Remote command: INIT:CONT ON

Operating Manual 1164.4556.12 - 06 4.27

R&S FSP Instrument Functions

Analyzer Mode

SINGLE
SWEEP

CONTINUE
SGL SWEEP

SWEEPTIME
MANUAL

The SINGLE SWEEP softkey starts n sweeps after triggering. The number of
sweeps is determined by the SWEEP COUNT softkey.

When working in the split-screen mode, the frequency ranges of the two windows
are swept one after the other.

If a trace is swept using TRACE AVERAGE or MAXHOLD, the value set via the
SWEEP COUNT softkey determines the number of sweeps. If 0 has been entered,
one sweep is performed.

Remote command: INIT:CONT OFF

The CONTINUE SGL SWEEP softkey repeats the number of sweeps set under
SWEEP COUNT, however without first deleting the trace.

This is particularly of interest when using the functions TRACE AVERAGE and
MAXHOLD, if previously recorded measurement results are to be taken into consid­eration for averaging / maximum search.

If SGL SWEEP DISP OFF is active, the screen is switched off also during repeated
sweeps.

Remote command: INIT:CONM

The SWEEPTIME MANUAL softkey activates the window for entering the sweep
time manually (see also BW menu).

SWEEPTIME
AUTO

SWEEP
COUNT

Remote command: SWE:TIME 10s

The SWEEPTIME AUTO softkey activates the automatic selection of the sweep time
as a function of the bandwidth of the resolution and video filters (see also BW
menu).

Remote command: SWE:TIME:AUTO ON

The SWEEP COUNT softkey activates the window for the entry of the number of
sweeps to be performed by R&S FSP after a single sweep has been started. If Trace
Average, Max Hold or Min Hold is activated, this also determines the number of
averaging or maximum search procedures.

Example

[TRACE1: MAX HOLD]
[SWEEP: SWEEP COUNT: {10} ENTER]
[SINGLE SWEEP]

R&S FSP performs the Max Hold function over 10 sweeps.

The permissible range for the sweep count is 0 to 32767. For sweep count = 0 or 1,
one sweep is performed. For trace averaging in the continuous-sweep mode,
R&S FSP performs running averaging over 10 sweeps if sweep count = 0; if sweep
count = 1, no averaging, maxhold or minhold is performed.

The sweep count is valid for all the traces in a diagram.

4.28 Operating Manual 1164.4556.12 - 06