This chapter provides safety-related information, an overview of the user documentation and the conventions used in the documentation.
This section provides an overview of the R&S FPL1000 user documentation. Unless
specified otherwise, you find the documents on the R&S FPL1000 product page at:
www.rohde-schwarz.com/manual/FPL1000
Introduces the R&S FPL1000 and describes how to set up and start working with the
product. Includes basic operations, typical measurement examples, and general information, e.g. safety instructions, etc.
A printed version is delivered with the instrument. A PDF version is available for download on the Internet.
1.1.2User manuals and help
Separate user manuals are provided for the base unit and the firmware applications:
●
Base unit manual
Contains the description of all instrument modes and functions. It also provides an
introduction to remote control, a complete description of the remote control commands with programming examples, and information on maintenance, instrument
interfaces and error messages. Includes the contents of the getting started manual.
●
Firmware application manual
Contains the description of the specific functions of a firmware application, including remote control commands. Basic information on operating the R&S FPL1000 is
not included.
The contents of the user manuals are available as help in the R&S FPL1000. The help
offers quick, context-sensitive access to the complete information for the base unit and
the firmware applications.
All user manuals are also available for download or for immediate display on the Internet.
1.1.3Service manual
Describes the performance test for checking compliance with rated specifications, firmware update, troubleshooting, adjustments, installing options and maintenance.
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1.1.4Instrument security procedures
1.1.5Printed safety instructions
1.1.6Data sheets and brochures
Preface
Documentation overview
The service manual is available for registered users on the global Rohde & Schwarz
information system (GLORIS):
https://gloris.rohde-schwarz.com
Deals with security issues when working with the R&S FPL1000 in secure areas. It is
available for download on the Internet.
Provides safety information in many languages. The printed document is delivered with
the product.
The data sheet contains the technical specifications of the R&S FPL1000. It also lists
the firmware applications and their order numbers, and optional accessories.
The brochure provides an overview of the instrument and deals with the specific characteristics.
See www.rohde-schwarz.com/brochure-datasheet/FPL1000
1.1.7Release notes and open source acknowledgment (OSA)
The release notes list new features, improvements and known issues of the current
firmware version, and describe the firmware installation.
The open-source acknowledgment document provides verbatim license texts of the
used open source software.
See www.rohde-schwarz.com/firmware/FPL1000
1.1.8Application notes, application cards, white papers, etc.
These documents deal with special applications or background information on particular topics.
See www.rohde-schwarz.com/application/FPL1000
1.1.9Calibration certificate
The document is available on https://gloris.rohde-schwarz.com/calcert. You need the
device ID of your instrument, which you can find on a label on the rear panel.
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1.2Conventions used in the documentation
1.2.1Typographical conventions
Preface
Conventions used in the documentation
The following text markers are used throughout this documentation:
ConventionDescription
"Graphical user interface elements"
[Keys]Key and knob names are enclosed by square brackets.
Filenames, commands,
program code
InputInput to be entered by the user is displayed in italics.
LinksLinks that you can click are displayed in blue font.
"References"References to other parts of the documentation are enclosed by quota-
All names of graphical user interface elements on the screen, such as
dialog boxes, menus, options, buttons, and softkeys are enclosed by
quotation marks.
Filenames, commands, coding samples and screen output are distinguished by their font.
tion marks.
1.2.2Conventions for procedure descriptions
When operating the instrument, several alternative methods may be available to perform the same task. In this case, the procedure using the touchscreen is described.
Any elements that can be activated by touching can also be clicked using an additionally connected mouse. The alternative procedure using the keys on the instrument or
the on-screen keyboard is only described if it deviates from the standard operating procedures.
The term "select" may refer to any of the described methods, i.e. using a finger on the
touchscreen, a mouse pointer in the display, or a key on the instrument or on a keyboard.
1.2.3Notes on screenshots
When describing the functions of the product, we use sample screenshots. These
screenshots are meant to illustrate as many as possible of the provided functions and
possible interdependencies between parameters. The shown values may not represent
realistic usage scenarios.
The screenshots usually show a fully equipped product, that is: with all options installed. Thus, some functions shown in the screenshots may not be available in your particular product configuration.
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2Welcome to the noise figure measurement
Welcome to the noise figure measurement application
Starting the noise application
application
The R&S FPL1-K30 is a firmware application that adds functionality to perform "noise
figure" measurements to the R&S FPL1000.
Noise Source Control
The Noise Source Control connector on the R&S FPL1000 is a prerequisite for the
R&S FPL1 Noise Figure measurements application.
This connector is part of the "Additional Interfaces" hardware option R&S FPL1-B5.
This user manual contains a description of the functionality that the application provides, including remote control operation.
Functions that are not discussed in this manual are the same as in the Spectrum application and are described in the R&S FPL1000 user manual.
The latest versions of the manuals are available for download at the product homepage.
www.rohde-schwarz.com/manual/FPL1000
Installation
Find detailed installing instructions in the getting started or the release notes of the
R&S FPL1000.
●Starting the noise application..................................................................................10
●Understanding the display information....................................................................11
2.1Starting the noise application
The "noise figure" measurement application adds a new type of measurement to the
R&S FPL1000.
To activate the R&S FPL1 Noise Figure measurements application
1. Select the [MODE] key.
A dialog box opens that contains all operating modes and applications currently
available on your R&S FPL1000.
2. Select the "Noise Figure" item.
The R&S FPL1000 opens a new measurement channel for the "noise figure" measurement application.
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Welcome to the noise figure measurement application
Understanding the display information
All settings specific to "noise figure" measurements are in their default state.
Multiple Channel Setups and Sequencer Function
When you activate an application, a new channel setup is created which determines
the measurement settings for that application ("Channel"). The same application can
be activated with different measurement settings by creating several "Channel"s for the
same application.
The number of channel setups that can be configured at the same time depends on the
available memory on the instrument.
Only one measurement can be performed at any time, namely the one in the currently
active channel setup. However, to perform the configured measurements consecutively, a Sequencer function is provided.
If activated, the measurements configured in the currently defined "Channel"s are performed one after the other in the order of the tabs. The currently active measurement is
indicated by a
The result displays of the individual channel setups are updated in the tabs (as well as
the "MultiView") as the measurements are performed. Sequential operation itself is
independent of the currently displayed tab.
symbol in the tab label.
For details on the Sequencer function, see the R&S FPL1000 user manual.
2.2Understanding the display information
The following figure shows the display as it looks for "noise figure" measurements. All
different information areas are labeled. They are explained in more detail in the following sections.
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Welcome to the noise figure measurement application
Understanding the display information
1
2
3
4
4
44
6
Figure 2-1: Screen layout of the noise figure measurement application
1 = Toolbar
2 = Channel Setup bar
3 = Diagram header
4 = Result display
5 = Softkey bar
6 = Status bar
Channel Setup bar information
In the R&S FPL1 Noise Figure measurements application, the R&S FPL1000 shows
the following settings:
5
Ref LevelReference level of the R&S FPL1000.
AttAttenuation of the R&S FPL1000.
RBWResolution bandwidth
SWTSweep time
AVGNumber of averages
ENRExcess noise ratio
For smart noise sources: also the provided temperature
2nd Stage CorrState of the 2nd stage correction.
Calibration DataDate and time of the current calibration data.
ModeCurrently selected measurement mode.
Window title bar information
For each diagram, the header provides the following information:
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Welcome to the noise figure measurement application
Understanding the display information
Figure 2-2: Window title bar information for the R&S FPL1 Noise Figure measurements application
1 = Window number
2 = Window type
3 = Trace color and number
4 = Trace mode
Status bar information
Global instrument settings, the instrument status and any irregularities are indicated in
the status bar beneath the diagram. Furthermore, the progress of the current operation
is displayed in the status bar.
Risk of damaging the instrument
Make sure not to overload the input mixer during calibration and the measurement. An
overload condition can damage or destroy the input mixer.
If an overload condition occurs, the R&S FPL1000 shows a corresponding message in
the status line ("RF OVLD" or "IF OVLD").
To avoid an overload during calibration or measurement, do one or more of the following:
●
Check and adjust the DUT "gain" settings
●
Check and adjust the ENR settings
●
Increase the reference level.
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3Measurements and result displays
Measurements and result displays
The R&S FPL1-K30 measures the "noise figure" of a DUT and displays the results
graphically and numerically. Each graphical result display shows the "noise figure" from
a different perspective. In the default configuration, the application shows the "noise
figure" of the DUT, the "gain" of the DUT and the corresponding "y-factor". In addition,
it shows the numerical results of the measurement.
The scale of the horizontal axis depends on the tuning mode.
Frequency list and swept measurements
In all graphical result displays, the horizontal axis represents the frequency. The displayed frequency is either the RF (radio frequency) or the IF (intermediate frequency).
The range depends on the frequency set you have currently defined. Because the
application only measures selected frequencies, it connects the results to draw a trace.
Negative "noise figure" and "noise temperature"
From a physical point of view, the "noise figure" and the "noise temperature" levels
have a positive range (including zero).
Due to the mathematical operations the application performs, the results can be negative. Sometimes this happens due to incorrect calibration or variance of measurement
values.
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out
in
SNR
SNR
Figure Noise
Measurements and result displays
Single frequency measurements
In all graphical result displays, the horizontal axis represents a chronological order of
measurement results for the frequency you are testing. The axis has no unit, but is
made up out of several index values that represent time. Each index value represents
one measurement point and therefore one measurement on the single frequency you
are analyzing. The size of the index (and thus number of results) depends on the number of (Measurement) Points that you have defined. Because the application only
measures at certain points in time, it connects the results to draw a trace.
The right diagram border represents the present (index = 0), values to the left represent past measurement results (index = -<x>). As soon as the application finishes a
single measurement, the measurement points are moved to the left, the new result is
added on the right. All other measurement points are moved down one position with
the most obsolete result falling out of the diagram (like in the roll mode of an oscilloscope).
Selecting the result display
►
Select the
icon in the toolbar or press the [MEAS] key.
The application enters the SmartGrid configuration mode.
For more information on the SmartGrid functionality, see the R&S FPL1000 Getting
Started.
Shows the "noise figure" of the DUT.
The "noise figure" is the ratio of the signal-to-noise ratio at the DUT input to the signal-
to-noise ratio at the DUT output.
The vertical axis shows the level of the "noise figure" in dB. The scale depends on the
settings in the "Display Configuration" dialog box.
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Measurements and result displays
Remote command:
LAY:ADD:WIND? '2',RIGH,NOIS see LAYout:ADD[:WINDow]? on page 97
Results:TRACe<t>[:DATA]? <Trace>,NOISe
Gain
Shows the "gain" characteristics of the DUT.
The vertical axis shows the level of the "gain" in dB. The scale depends on the settings
in the "Display Configuration" dialog box.
Remote command:
LAY:ADD:WIND? '2',RIGH,GAIN see LAYout:ADD[:WINDow]? on page 97
Results:TRACe<t>[:DATA]? <Trace>,GAIN
Noise Temperature
Shows the "noise temperature" characteristics of the DUT.
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constant Boltzmannk
BandwidthB
PowerP
with
eTemperatur Noise
kB
P
off source noise with[dB] power Noise
on source noise with[dB] power Noise
with
FactorY
off
on
off
on
N
N
N
N
Measurements and result displays
The vertical axis shows the "noise temperature" in Kelvin. The scale depends on the
settings in the "Display Configuration" dialog box.
Remote command:
LAY:ADD:WIND? '2',RIGH,TEMP see LAYout:ADD[:WINDow]? on page 97
Results: TRACe<t>[:DATA]? <Trace>,TEMPerature
Y-Factor
Shows the ratio of the hot and the cold power of the DUT.
The "Y-factor" indicates the quality of measurement tolerances and uncertainties. To
get the result, the application measures the DUT power with the noise source turned
on (hot power) and the noise source turned off (cold power).
The vertical axis shows the linear relation. The scale depends on the settings in the
"Display Configuration" dialog box.
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Measurements and result displays
Remote command:
LAY:ADD:WIND? '2',RIGH,YFAC see LAYout:ADD[:WINDow]? on page 97
Results: TRACe<t>[:DATA]? <Trace>,YFACtor
ENR Measured
Shows the results of the ENR measurement.
To measure the ENR of a noise source, first attach a noise source with known ENR to
the device, enter the ENR of this noise source to the calibration ENR table and calibrate using this one. Then, attach the unknown noise source to the device and perform
a measurement ("Run Single") with this one. The graph shown in the ENR Measured
display and the results for ENR Measured in the Result Summary will be the ENR of
the noise source at the measured frequencies. The vertical axis shows the level of the
measured ENR in dB. The scale depends on the settings in the "Display Configuration"
dialog box.
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Measurements and result displays
Remote command:
LAY:ADD:WIND? '2',RIGH,ENR see LAYout:ADD[:WINDow]? on page 97
Results: TRACe<t>[:DATA]? <Trace>,ENR
Power (Hot)
Shows the absolute power characteristics at the instrument input. The noise source is
turned on.
The vertical axis shows the power in dBm. The scale depends on the settings in the
"Display Configuration" dialog box.
Remote command:
LAY:ADD:WIND? '2',RIGH,PHOT see LAYout:ADD[:WINDow]? on page 97
Results: TRACe<t>[:DATA]? <Trace>,PHOT
Power (Cold)
Shows the absolute power characteristics at the instrument input. The noise source is
turned off.
The vertical axis shows the power in dBm. The scale depends on the settings in the
"Display Configuration" dialog box.
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off source noise with[dB] power Noise
on source noise with[dB] power Noise
with
FactorY
off
on
off
on
N
N
N
N
Measurements and result displays
Remote command:
LAY:ADD:WIND? '2',RIGH,PCOL see LAYout:ADD[:WINDow]? on page 97
Results: TRACe<t>[:DATA]? <Trace>,PCOLd
Cal Y-Factor
Shows the ratio of the hot and the cold power measured during calibration.
The "Y-factor" indicates the quality of measurement tolerances and uncertainties. To
get the result, the application measures the power with the noise source turned on (hot
power) and the noise source turned off (cold power), but without the DUT inserted.
The vertical axis shows the linear relation. The scale depends on the settings in the
"Display Configuration" dialog box.
Remote command:
LAY:ADD:WIND? '2',RIGH,CYF see LAYout:ADD[:WINDow]? on page 97
Results: TRACe<t>[:DATA]? <Trace>,CYFactor
Cal Power (Hot)
Shows the absolute power characteristics at the instrument input during the calibration
measurement. The noise source is turned on, the DUT is not inserted.
The vertical axis shows the power in dBm. The scale depends on the settings in the
"Display Configuration" dialog box.
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Measurements and result displays
Remote command:
LAY:ADD:WIND? '2',RIGH,CPH see LAYout:ADD[:WINDow]? on page 97
Results: TRACe<t>[:DATA]? <Trace>,CPHot
Cal Power (Cold)
Shows the absolute power characteristics at the instrument input during the calibration
measurement. The noise source is turned off, the DUT is not inserted.
The vertical axis shows the power in dBm. The scale depends on the settings in the
"Display Configuration" dialog box.
Remote command:
LAY:ADD:WIND? '2',RIGH,CPC see LAYout:ADD[:WINDow]? on page 97
Results: TRACe<t>[:DATA]? <Trace>,CPCold
Result Table
Shows the measurement results in numerical form in a table.
The contents of the table depend on the "Display Settings". By default it shows the
"noise figure", "gain" and "y-factor" results. Each row represents one measurement
point. Each column represents one result type. The first column shows the measurement frequency.
The result table shows either the RF or the IF, depending on your selection.
For more information, see Chapter 6.1.2, "Configuring numerical results", on page 77.
Remote command:
LAY:ADD:WIND? '2',RIGH,RES see LAYout:ADD[:WINDow]? on page 97
Results: TRACe<n>[:DATA]?on page 103
Table items: DISPlay[:WINDow<n>]:TABLe:ITEMon page 149
Current Values
Shows the result at the current measurement point.
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Measurements and result displays
The contents of the "Current" result display are updated as soon as a new measurement point is analyzed.
The result types shown in the table depend on the "Display Settings". By default it
shows the results for the "Noise Figure", "Gain" and "Y-Factor" result type. Each row
represents one result type. The first column shows the result type, the second column
shows the result.
For more information, see Chapter 6.1.2, "Configuring numerical results", on page 77.
Marker Table
Shows the marker characteristics in numerical form in a table.
The size of the table depends on the number of active markers and the way you have
configured the table in the "Result Config" dialog box. For more information, see Chap-
ter 6.3, "Using markers", on page 81 and Chapter 6.1.2, "Configuring numerical
results", on page 77.
The first four columns of the table are fix.
●
Type
Shows the marker type. 'M' represents a normal marker, 'D' represents a delta
marker.
●
Ref
Shows the reference marker for relative delta markers.
●
Trc
Shows the trace that the marker is positioned on.
●
X-value
Shows the horizontal position (frequency) of the marker.
For normal markers, the position is an absolute value. The position of delta markers is relative to another marker.
●
<Result>
Shows the measurement result at the marker position.
For normal markers, the result is an absolute value. Results for delta markers are
relative to another marker.
Remote command:
LAY:ADD:WIND? '2',RIGH,MTAB see LAYout:ADD[:WINDow]? on page 97
Results:
CALCulate<n>:MARKer<m>:Y? on page 168
CALCulate<n>:DELTamarker<m>:Y? on page 171
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4Measurement basics
Measurement basics
Tuning modes
The measurement basics contain background information on the terminology and principles of "noise figure" measurements.
"Noise figure" measurements determine the noise that a device under test (DUT) adds
to a signal as that signal passes through the DUT.
Basically, the application calculates the "noise figure" of a DUT based on the characteristics of the DUT that have been measured and a noise source whose properties are
known. Therefore, the Noise Source Control connector on the R&S FPL1000 is a prerequisite for the R&S FPL1 Noise Figure measurements application.
In addition to the noise characteristics of a DUT, the application is also able to determine several more DUT characteristics like its "gain" or its "noise temperature" characteristics.
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4.1.1Swept measurements
Measurement basics
Tuning modes
The application provides several measurement modes or tuning modes.
●Single frequency measurements.............................................................................25
The sweep tuning mode performs measurements on a set of discrete frequencies
based on the frequency parameters. Each measurement analyzes the noise characteristics of the corresponding frequency or measurement point.
For swept measurements, the application automatically determines the measurement
frequencies and combines them in a frequency list.
Such a frequency set is the result of the frequency and span information that you have
provided. The frequency and span information is made up out of the center frequency,
the span, the start and the stop frequency. In combination with the measurement points
or the frequency table step size, the application calculates the contents of the frequency table.
The center frequency is the frequency in the center of the frequency band you are
measuring. Thus, it is defined either by the span, or the start and stop frequencies.
The measurement points is the number of entries in a frequency list and thus the
number of measurements that the application performs during a "noise figure" measurement.
The stepsize defines the distance between two measurement points. It is constant for
all measurement points.
If the stepsize is larger than the distance between start and stop frequency, the frequency table consists of the start and stop frequencies only.
4.1.2Frequency table measurements
The frequency table tuning mode also performs measurements on a set of frequencies based on the contents of a frequency list. Each measurement analyzes the noise
characteristics of the corresponding frequency.
Compared to a swept measurement, you can customize the contents of the frequency
list. Thus, you can add frequencies that are independent of the frequency stepsize and
the number of measurement points.
Frequency tables also allow you to define a variable RBW and sweep time, depending
on the current frequency of the sweep point (see "Variable RBW and sweep time for
low-frequency measurements"on page 35 and Chapter 5.2.3, "Using a frequency
table", on page 45).
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4.1.3Single frequency measurements
Measurement basics
Measurement modes
The single frequency tuning mode performs one or several consecutive measurements on a single frequency. You can perform the measurement on any frequency that
is supported by the hardware you are using.
Single frequency measurements are a way to facilitate manual adjustments for "noise
figure" measurements. They also allow you to get an idea about how the "noise figure"
at a particular frequency change over time.
Note that sweep lists or frequency tables are not considered in this measurement
mode.
Single frequency measurement results
For single frequency measurements, the same set of graphical result displays is available as for frequency list measurements ("Noise Figure", "Gain" etc.). Note, however,
that the x-axis has no unit, but shows a series of results taken for a single frequency.
The number of displayed results depends on the number of measurement points you
have defined.
For more information, see Chapter 3, "Measurements and result displays", on page 14.
In addition, you can also view the results in the Result Table in numerical form.
Single frequency measurements are not available when you are using a resistor as a
noise source.
4.2Measurement modes
In some cases, the Power (Hot) and Power (Cold) results require two different noise
sources with different temperature characteristics (cold and hot). Measurements with a
resistor noise source are such a case.
Usually, noise sources with diode characteristics are used for "Noise Figure" measurements. These noise sources have two states, on and off. When they are supplied with
power (state = on), the application measures the hot power, when they are not supplied
with power (state = off), it measures the cold power. Turning the noise source on and
off is automatically done by the application, so that you can get the hot and cold power
characteristics in a single step.
This automatic measurement mode is the default measurement mode of the R&S
FPL1 Noise Figure measurements application.
A resistor noise source, however, requires two resistors, one hot and one cold. You
have to substitute the hot resistor by the cold resistor to measure first the hot and then
the cold power. For these cases, the application provides a manual measurementmode. This measurement mode is automatically selected when you select a "Noise
Source"on page 51 with resistor characteristics, but is not restricted to those cases.
The manual measurement mode is available for measurements and the calibration
stage.
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Measurement basics
Measurement modes
Performing a manual measurement
In manual measurement mode, you have to measure (or calibrate) the hot and cold
power characteristics of the DUT separately. When you start the measurement, the
application opens a dialog box that allows you to select the type of measurement to
perform next.
Recommended order of measurements
Note that it is recommended that you begin with the hot power measurement.
Furthermore, calibration always begins with the hot power measurement.
In case the hot power has to be measured first, the cold power measurement is
unavailable:
When the first measurement is done, you can change the test setup by connecting the
other resistor. Then start the second measurement.
In the dialog box, the measurement stage that is already done is labeled green.
In addition, the application shows the missing calibration and measurement steps in
the channel bar.
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4.3DUT types
Measurement basics
DUT types
Clearing results
To replace the previous calibration or measurement results, clear the currently stored
data using the "Clear Calibration Results" or "Clear Measurement Results" function.
Returning to automatic measurement mode
When you are in automatic measurement mode and select a noise source with resistor
characteristics, the application automatically selects the manual measurement mode.
When you are in manual measurement mode and select a noise source with diode
characteristics, you have to select the automatic measurement mode deliberately in
the "Sweep" menu.
"Noise figure" measurements are possible on DUTs with a wide variety of characteristics. The DUT characteristics not only affect the test setup, but also determine the way
the application populates the frequency list for swept measurements.
The R&S FPL1 Noise Figure measurements application supports measurements on
DUTs that work on a fixed frequency as well as measurements on frequency-converting DUTs.
●Measurements on linear DUTs (direct measurement).............................................27
●Measurements on frequency converting DUTs....................................................... 27
4.3.1Measurements on linear DUTs (direct measurement)
For a linear DUT, the RF frequency remains the same between its input and output.
For measurements on such DUTs, it is sufficient to measure the signal's RF frequency
without any additional equipment (like a local oscillator). A typical linear DUT is an
amplifier, for example.
The test setup for measurements on such DUTs usually consists of the noise source,
the DUT and an analyzer. If necessary, the measurement also considers loss that
occurs somewhere in the measurement path.
For linear DUTs, the contents and layout of the "Overview" dialog box represents the
configuration of a typical test setup.
4.3.2Measurements on frequency converting DUTs
A frequency converting DUT converts the RF frequency to an intermediate frequency
(IF) using the local oscillator (LO). A frequency-converting DUT either converts the RF
frequency to a lower IF (down-conversion) or a higher IF (up-conversion).
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Measurement basics
Image frequency rejection
If you have selected a frequency-converting DUT measurement mode, the layout of the
"Overview" dialog box adds the local oscillator to the test setup.
The local oscillator can have a fixed or a variable frequency. If the LO frequency is
fixed, the intermediate frequency (IF) resulting from the conversion process is variable
(depending on the input signal). If the LO frequency is variable, the IF has to be fixed.
The R&S FPL1 Noise Figure measurements application supports only the fixed LO frequency measurement method.
Fixed LO frequency
If you select one of the fixed LO measurement modes, the LO frequency is the same
for all entries in the frequency list. The IF frequency for each entry is variable and is the
result of the equation the selected mode is based on.
●
fRF + fLO for up-converters
●
fRF - fLO for down-converters
The fixed LO measurement modes are, for example, required for measurements on
satellite converters.
4.4Image frequency rejection
Frequency converting DUTs convert a radio frequency (RF) to an intermediate frequency (IF). The IF is lower than the RF for down-converting DUTs, and higher than
the RF for up-converting DUTs.
In a basic test setup, the image frequency of the RF signal is also converted to the IF.
Depending on the DUT, this effect can be wanted or even necessary, or not. To avoid
measurement errors of the "noise figure" and "gain" of up to 3 dB, make sure to use
the appropriate measurement configuration.
Basically, you can distinguish between single sideband (SSB) mixers, double sideband
(DSB) mixers, and mixers that partly suppress a sideband. If a sideband is not needed
or only partly needed, you can reject the image frequency. If you do so, the application
activates a filter that suppresses the image frequency to a certain extent.
The following illustrations help you configure the measurement correctly.
For more information on how to configure image rejection, see "Image Rejection"
on page 48.
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Measurement basics
Image frequency rejection
Double sideband measurements
Double sideband mixers use both sidebands to the same extent. Both RF and image
frequency are converted. In that case, turn off image rejection.
fLO= frequency of the local oscillator
fIF= intermediate frequency = fRF ± f
fRF= lower sideband = fLO - f
f
= upper sideband = fLO + f
image
LO
IF
IF
If image rejection is on, the results have a 3 dB error. That means "noise figure" results
are 3 dB lower than they should be. "Gain" results are 3 dB higher.
Single sideband measurements
Single sideband mixers use a single sideband only. In that case, you have to suppress
the sideband that is not required. If you do so, the measurement is like on an amplifier.
To suppress a sideband completely, it is best to set the image rejection to the maximum amount possible (999.99 dB).
Partial sideband suppression
For measurements on mixers with a low image frequency rejection, there are two test
scenarios.
●
Mixers whose image rejection is known.
●
Mixers whose image rejection is unknown.
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Measurement basics
Image frequency rejection
For mixers whose image rejection is known, define the magnitude of image rejection in
dB as accurately as possible. Otherwise, measurement results ("noise figure" and
"gain") deviate between 0 dB to 3 dB.
If you do not know the image rejection characteristics of a mixer, use a custom test
setup including an additional filter. You also have to know the "gain" characteristics of
the DUT.
(1)
= Test setup for calibration
(2) = Test setup for "noise figure" measurement
In the test setup shown above, a lowpass filter prevents unwanted noise from being fed
in at the image frequency.
Depending on the position of the frequency bands, you might need a highpass or
bandpass filter for the RF frequency instead of the lowpass filter. The important point is
that unwanted noise is not converted by a further receive path of the mixer. The
unwanted noise at the receive frequency must not be reduced. The insertion loss must
be considered, if applicable.
With this test setup, the measurement on a mixer without sideband suppression is the
same as SSB measurements.
To take the characteristics of the filter into account, include the insertion loss of the filter at the RF. To consider the actual filter suppression at the image frequency, include
the actual attenuation for the image rejection.
Harmonics mixer measurement
For a harmonics mixer, the input signals are not only converted to the IF by the wanted
harmonic. The harmonic of the LO signal produced in the mixer is also converted.
Often, the mixer even features a lower conversion loss for unwanted harmonics. For
measurements on this type of mixer, you have to use a bandpass filter. The filter
ensures that there is only noise at the desired frequency at the input of the DUT. This
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4.5Calibration (2nd stage correction)
Measurement basics
Calibration (2nd stage correction)
measurement is similar to measurements on a mixer with an average sideband suppression.
The calibration procedure of the application measures the inherent noise of the
R&S FPL1000 you are using. Performing calibration is therefore recommended, as it
increases the accuracy of measurement results. The results get more accurate
because the application takes the inherent noise of the analyzer into account while it
calculates the results.
Calibration for "noise figure" measurements is also known as 2nd stage correction.
This term is used because in a typical "noise figure" test setup, the DUT represents the
first stage and the analyzer the second stage in the test setup.
The 2nd stage correction is a calibration that is specific to "noise figure" measurements. It is independent of the overall calibration state of the analyzer and does not
calibrate the analyzer.
For successful calibration, you need additional equipment.
●
Noise source
The noise source is like a calibration standard. It provides a reference with known
noise characteristics that allows the application to determine the inherent noise of
the analyzer you are using.
During the calibration, the application measures the inherent noise characteristics of
the analyzer at the set of measurement frequencies.
Thus, the 2nd stage correction is valid for a particular instrument configuration, the
room temperature and the instrument temperature. As long as this configuration stays
the same, calibration data remains valid.
Calibrating single frequency measurements
Like for all other measurements of the R&S FPL1 Noise Figure measurements application, perform a calibration before a single frequency measurement for increased accuracy.
There is an easy way to calibrate single frequency measurements, if you already calibrated the application for swept or list measurements. If the single frequency is part of
the frequency list, the measurement is already calibrated for that frequency and no further steps are necessary. The application recalls the last calibration values when you
switch back to sweep mode or frequency table mode.
Only if you use a single frequency that is not part of the frequency list, you must calibrate this frequency point first.
●
Interpolation
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Measurement basics
Calibration (2nd stage correction)
If you change the frequency, while the frequency span stays the same or is
reduced, the application interpolates the correction data for the new measurement
points. A new calibration is not required.
However, measurements based on interpolated data can result in an increased
measurement uncertainty. Highly accurate measurements that are conform to the
values specified in the data sheet are only possible at calibrated measurement
points.
Note that useful interpolation is possible only if essential calibration parameters
(e.g. impedance or attenuation) change only slightly. This is the case if the distance
between the original calibration points is sufficiently small.
If the span increases compared to the span during calibration, a new calibration is
necessary.
If the application interpolates the calibration data, it shows a corresponding label in
the channel bar and a warning message in the status bar.
●
Invalid calibration
If you change one of the amplitude parameters (e.g. the attenuation), calibration is
labeled invalid. In that case, calibration is not accurate, because the settings are
not in line with the settings at the time the R&S FPL1000 has been calibrated. If
calibration is invalid, repeat the calibration or restore the settings as they were during the calibration.
Saving calibration data
If you save the current configuration or measurement results to a data set, calibration
data is part of that data set.
For more information on saving and restoring data sets, see the "Storing and Recalling
Instrument Settings and Measurement Data" chapter in the R&S FPL1000 user manual.
The picture below shows a typical calibration setup that includes a noise source.
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Measurement basics
Calibration (2nd stage correction)
Figure 4-1: Noise figure calibration setup
1. Connect the noise source directly and without a cable to the RF input of the analyzer.
2. Connect the noise source to the +28 V voltage supply (Noise Source Control connector) on the back of the R&S FPL1000.
To connect the noise source to the voltage supply, you need a coaxial cable.
After you have set up calibration, there are several ways to start calibration.
●
In the "Noise Overview" dialog box, press the "Calibrate" button.
●
In the "Sweep" menu, press the "Calibrate" softkey.
Calibration Save
If the user has performed a valid calibration on the instrument, the calibration results
can be saved by using the "Calibration Save" button in the "Export" dialog. This provides the possibility to use once stored calibration results at a later point.
Remote command:
[SENSe:]CORRection:SAVE on page 128
Calibration Recall
Calibration results that have been stored once on the instrument can be recalled by
using the "Calibration Recall" button in the "Import" dialog.
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Measurement basics
Using smart noise sources
To achieve a valid calibration by importing a saved one, all parameters of
R&S FPL1000-K30 must match exactly to the ones that have been used for the calibration. At the import of a calibration, a preview dialog is shown which contains all relevant parameters of the calibration to be imported and an indication (green / red) if they
match to the current instrument and option settings. Only if the calibration context summary is green, the calibration import can be done. If the calibration context summary is
red, importing the calibration results would lead to an invalid calibration status for the
current settings. Thus the calibration results cannot be imported in this case. If the calibration context summary is green but some of the individual entries are red (i.e. they
differ from the current settings), the calibration results still can be imported. The import
will then overwrite the red marked settings with the ones from the stored calibration to
ensure the settings match.
Remote command:
[SENSe:]CORRection:RECall on page 128
4.6Using smart noise sources
A smart noise source (SNS) provides its own ENR and uncertainty tables and a temperature value from an internal measurement. Thus, accuracy is improved and less
configuration efforts are required.
When you connect a smart noise source, the R&S FPL1000 automatically loads its
ENR table and stores it for future measurements. The ENR table remains stored on the
instrument even after the noise source is disconnected. If the table already exists on
the R&S FPL1000, the contents are updated, if necessary. The contents of the most
recently loaded SNS ENR table are also stored as the "default" ENR table. Thus, they
remain available even if the noise source type is changed, for example to "noise
diode". The ENR tables for smart noise sources are shown for reference only and can-
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4.7Separating signals by selecting an appropriate reso-
Measurement basics
Separating signals by selecting an appropriate resolution bandwidth
not be edited in the R&S FPL1 Noise Figure measurements application. The name of
each ENR table contains the serial number of the SNS.
Test Setup
Connect the smart noise source to the Lemosa Power Sensor / Noise Source Control
connector on the R&S FPL1000. (For models without a Lemosa connector, connect the
SNS to the BNC Noise source control connector and a USB connector on the
R&S FPL1000.) Then connect the SNS output to the DUT or the RF Input connector on
the R&S FPL1000. Only one SNS can be active on the R&S FPL1000 at any time.
The identification and setup procedure after connecting the FS-SNS may take up to 10
seconds.
lution bandwidth
The resolution bandwidth defines the 3 dB bandwidth of the resolution filter to be used.
An RF sinusoidal signal is displayed according to the passband characteristic of the
resolution filter (RBW), i.e. the signal display reflects the shape of the filter.
The highest sensitivity is obtained at the smallest bandwidth (1 Hz). If the bandwidth is
increased, the reduction in sensitivity is proportional to the change in bandwidth.
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.
The higher spectral resolution with smaller bandwidths is won by longer sweep times
for the same span. The sweep time has to allow the resolution filters to settle during a
sweep at all signal levels and frequencies to be displayed.
If the RBW is too large, signal parts that are very far away (e.g. from a different signal)
are considered in the measurement and distort the results. The displayed noise increases.
If the RBW is too small, the measurement time increases.
Variable RBW and sweep time for low-frequency measurements
Usually, a constant RBW and sweep time is used for the entire measurement. However, for low-frequency measurements (under 10 MHz), smaller bandwidths and longer
sweep times are required to improve accuracy of the results. Using a small RBW and
long sweep time for the entire span would increase measurement time significantly. In
this case, a variable RBW and sweep time can be defined for lower frequencies,
depending on the current frequency of the sweep point. The variable RBW and sweep
times are defined in the frequency table (see Chapter 5.2.3, "Using a frequency table",
on page 45). The defined RBW and sweep times are also included in a table export.
In the channel bar, the bandwidth and sweep time range of the variable values is indicated.
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4.8Analyzing several traces - trace mode
Measurement basics
Using markers
The trace mode determines the way the data is processed and displayed. The application provides the following trace modes.
Table 4-1: Overview of available trace modes
Trace ModeDescription
BlankHides the selected trace.
Clear WriteOverwrite mode: the trace is overwritten by each sweep. This is the default setting.
ViewThe current contents of the trace memory are frozen and displayed.
Each time the trace mode is changed, the selected trace memory is cleared.
The default trace mode for the first trace is Clear/Write. For trace 2-4, the default trace
mode is "Blank". If you require another mode, you have to set it manually.
As you can have up to four traces simultaneously, you can compare the results with
different measurement configurations. For example, freeze a trace and use it as a reference trace.
If you change the scaling of the y-axis, the R&S FPL1000 automatically adapts the
trace data to the changed display range. Thus, you can perform an amplitude zoom
after the measurement to show details of the trace.
4.9Using markers
Markers are used to mark points on traces, to read out the results of a particular measurement point or compare results of different traces. The noise application provides
four markers.
When you activate a marker, the application automatically positions it on the first measurement point (left border of the diagram) of trace 1, regardless of how many traces
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Measurement basics
Using markers
are active. A marker is always positioned on the same horizontal position in all active
measurement windows. If you change the position of a marker in one window, the
application adjusts the position of that marker in all other measurement windows. Thus,
the marker results for a specific marker are always for the same frequency, which
makes it easier to compare results.
Markers in single frequency mode
When you use a marker for single frequency measurements, the marker is positioned
on a particular index value and not a particular measurement point. This means that
during continuous measurements, the marker remains on the index value you have put
it on. It does not move down the line with the results.
To move a marker, you can use several methods.
●
Enter a particular measurement frequency in the input field that opens when you
activate a marker.
●
Move the marker around with the rotary knob or the cursor keys.
●
Drag the marker around using the touchscreen.
All markers can be used either as normal markers or delta markers. A normal marker
indicates the absolute signal value at the defined position in the diagram. A delta
marker indicates the value of the marker relative to the specified reference marker (by
default marker 1).
The application always positions the marker on the trace with the lowest number that is
in Clear/Write trace mode. To set the marker on another trace, use the "Marker to
Trace" function. With this function, you can also position a marker on a trace that is in
"View" trace mode, e.g. to compare measurement results. Note that at least one active
marker has to be a normal marker.
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Measurement basics
Using markers
The application shows the results at the marker position directly in the diagram area
(up to two markers) or in the marker table (if you use more than two markers).
Marker information in diagram area
By default, the results of the last two markers or delta markers that were activated are
displayed in the diagram area.
The following information is displayed there:
●
The marker type (M for normal, D for delta, or special function name)
●
The marker number (1 to 4)
●
The assigned trace number in square brackets [ ]
●
The marker value on the y-axis
●
The marker position on the x-axis
Marker information in marker table
In addition to the marker information displayed within the diagram area, a marker table
can be displayed in a separate window. For more information on the contents of the
marker table, see "Marker Table"on page 22.
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5Configuration
Configuration
Configuration overview
"Noise figure" measurements require a special application on the R&S FPL1000, which
you activate using the [MODE] key.
The Noise Source Control connector on the R&S FPL1000 is also a prerequisite for the
R&S FPL1 Noise Figure measurements application. Without this connector, no measurement can be performed.
This connector is part of the "Additional Interfaces" hardware option R&S FPL1-B5.
When you activate a measurement channel in the R&S FPL1 Noise Figure measurements application, a measurement for the input signal is defined with the default configuration. The "Noise Figure" menu is displayed and provides access to the most
important configuration functions.
Unavailable hardkeys
Note that the [AMPT], [BW], and [TRIG] keys have no contents and no function in the
R&S FPL1 Noise Figure measurements application.
●Configuring inputs and outputs of the R&S FPL1000............................................. 74
5.1Configuration overview
Throughout the measurement channel configuration, an overview of the most important
currently defined settings is provided in the "Overview". The "Overview" is displayed
when you select the "Overview" icon, which is available at the bottom of all softkey
menus.
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Configuration
Configuration overview
In addition to the main measurement settings, the "Overview" provides quick access to
the main settings dialog boxes. The individual configuration steps are displayed in the
order of the data flow. Thus, you can easily configure an entire measurement channel
from input over processing to output and analysis by stepping through the dialog boxes
as indicated in the "Overview".
In particular, the "Overview" provides quick access to the following configuration dialog
boxes (listed in the recommended order of processing):
To perform a calibration
1. Noise Source
See Chapter 5.4, "Configuring the noise source", on page 49.
2. Spectrum Analyzer
See Chapter 5.6, "Configuring the analyzer", on page 62.
3. Calibration
See "Calibrate"on page 73
To perform a measurement
1. Noise Source
See Chapter 5.4, "Configuring the noise source", on page 49.
2. Input and output losses
See Chapter 5.5, "Configuring additional loss", on page 57.
3. DUT configuration
See Chapter 5.3, "Selecting DUT characteristics", on page 48
4. Spectrum Analyzer
See Chapter 5.6, "Configuring the analyzer", on page 62.
5. Display Configuration
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Configuration
Defining the measurement frequency
See Chapter 6.1, "Configuring the display", on page 75
To configure settings
► Select any button in the "Overview" to open the corresponding dialog box.
Select a setting in the channel bar (at the top of the measurement channel tab) to
change a specific setting.
Preset Channel Setup
Select the "Preset Channel" button in the lower left-hand corner of the "Overview" to
restore all measurement settings in the current channel setup to their default values.
Note: Do not confuse the "Preset Channel" button with the [Preset] key, which restores
the entire instrument to its default values and thus closes all channel setups on the
R&S FPL1000 (except for the default channel setup)!
Remote command:
SYSTem:PRESet:CHANnel[:EXEC] on page 96
Specific Settings for
The channel setup can contain several windows for different results. Thus, the settings
indicated in the "Overview" and configured in the dialog boxes vary depending on the
selected window.
Select an active window from the "Specific Settings for" selection list that is displayed
in the "Overview" and in all window-specific configuration dialog boxes.
The "Overview" and dialog boxes are updated to indicate the settings for the selected
window.
5.2Defining the measurement frequency
●Defining a frequency set......................................................................................... 41
●Configuring single frequency measurements..........................................................44
●Using a frequency table.......................................................................................... 45
5.2.1Defining a frequency set
Access: "Overview" > "DUT" > "Frequency Config"
These settings define the frequency characteristics for the measurement.
The information in this tab is also the basis for an automatic population of the frequency table. All parameters of this dialog are interdependent. If you change one
parameter, at least one other parameter is changed by the application.
If you change a frequency set, perform a new calibration to ensure accurate results.
Selects the tuning or measurement mode.
For more information, see Chapter 4.1, "Tuning modes", on page 23.
Tuning mode selection is also available via softkeys ("Sweep Mode", "Frequency Table
Mode", "Single Frequency Mode") in the "Sweep" menu.
Note: A preamplifier can be activated or deactivated individually for different tuning
modes. When you switch tuning modes, the defined preamplifier state is adapted.
"Sweep"
"Frequency
Table"
"Single Frequency"
Remote command:
Frequency sweep measurement:
[SENSe:]CONFigure:LIST:CONTinuous on page 106
[SENSe:]CONFigure:LIST:SINGle on page 106
INITiate<n>[:IMMediate] on page 144
Single frequency measurement:
[SENSe:]CONFigure:FREQuency:CONTinuous on page 105
The measurement is based on an automatically generated frequency
set.
The measurement is based on a customized frequency table.
For more information, see Chapter 5.2.3, "Using a frequency table",
on page 45.
The measurement measures a single frequency only.
For more information, see Chapter 5.2.2, "Configuring single fre-
quency measurements", on page 44.
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Configuration
Defining the measurement frequency
[SENSe:]CONFigure:FREQuency:SINGle on page 105
INITiate<n>[:IMMediate] on page 144
Center
Defines the center of the measurement frequency range.
If you change the center frequency, the application changes the start and stop fre-
quency according to the span you have set.
The "Center" setting is also available via the [FREQ] key.
Remote command:
Frequency list measurement:
[SENSe:]FREQuency:CENTer on page 106
Single frequency measurement:
[SENSe:]FREQuency:SINGle on page 108
Span
Defines the measurement span.
If you change the span, the application changes the start frequency, the stop frequency
and the stepsize according to the center frequency and the measurement points.
The "Span" setting is also available via the [SPAN] key.
Remote command:
[SENSe:]FREQuency:SPAN on page 108
Start and Stop Frequency
Defines the start and stop frequencies.
If you change the start or stop frequency, the application changes the center frequency,
the span and the measurement points according to the new values and the stepsize.
The "Start" and "Stop" settings are also available via the [FREQ] key.
Remote command:
Start frequency:
[SENSe:]FREQuency:STARt on page 109
Stop frequency:
[SENSe:]FREQuency:STOP on page 109
(Measurement) Points
Defines the measurement points.
For frequency list measurements, the number of measurement points corresponds to
the number of entries in the frequency table. The number of points displayed in the
graphical results is also the same.
If you change the measurement points, the application changes the stepsize according
to the span.
The "Points" setting is also available via the [SPAN] key.
Remote command:
[SENSe:]FREQuency:POINts on page 107
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5.2.2Configuring single frequency measurements
Configuration
Defining the measurement frequency
Step
Defines the frequency step size in the frequency table.
The stepsize corresponds to the distance between two consecutive measurement
points.
If you change the stepsize, the application changes the measurement point according
to the span.
The "Stepsize" setting is also available via the [FREQ] key.
Remote command:
Defines the frequency that the single frequency measurement is performed on.
The "Single" setting is also available via the [FREQ] key.
Remote command:
[SENSe:]FREQuency:SINGle on page 108
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Configuration
Defining the measurement frequency
Coupled to Sweep List
Couples or decouples frequency selection to the contents of a sweep list.
If you couple the frequency to the sweep list, the application allows you to select only
the frequencies currently part of the frequency list. If you enter another frequency, the
application automatically selects the nearest frequency of the frequency list. If the frequency list has been calibrated previously, calibration remains valid for those frequencies when you change the tuning mode.
If you turn off the coupling, you can define any frequency for single frequency measurements. Note, however, that you have to calibrate the measurement for that frequency.
Remote command:
[SENSe:]FREQuency:SINGle:COUPled on page 108
(Measurement) Points
Defines the number of measurement points for single frequency measurements.
For single frequency measurements, the number of measurement points corresponds
to the number of measurements (index values) performed on a single frequency.
For more information, see "Single frequency measurements"on page 15.
The "Points" setting is also available via the [SPAN] key.
Remote command:
Shows the current measurement points.
The table is made up of one column that represents the measurement frequency. Each
frequency corresponds to one measurement point. The length of the table is variable
(up to a maximum of 10001 points).
When you perform measurements in "Sweep" or "Single Frequency" tuning mode, the
contents of the table have no effect on the measurement.
When you select a table entry in "Frequency Table" tuning mode, you can edit it or add
a new frequency below the selected frequency. A new frequency has to be higher than
the last table entry and lower than the next table entry.
If the RBW and sweep time settings are set to "variable" in the measurement settings
(see Resolution Bandwidth (RBW) and "Sweep Time"on page 63), you can also
define those values in the frequency table.
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Configuration
Defining the measurement frequency
Select Populate Table to predefine the RBW and sweep times to be used. For each
sweep point with a frequency under 10 MHz in the table, suitable settings are defined.
For higher frequencies, the values provided in the measurement settings are used
(indicated by "--" as they are automatically updated if the measurement settings
change.) All predefined values in the table can be overwritten manually.
The defined RBW and sweep times are also included in a table export.
See also "Variable RBW and sweep time for low-frequency measurements"
on page 35.
Clear Table
Deletes the contents of the table.
Populate Table
Populates or restores the measurement frequencies based on the center frequency,
the start and stop frequencies, the span, the stepsize and the number of measurement
points.
If the RBW and sweep time settings are set to "variable" in the measurement settings
(see Resolution Bandwidth (RBW) and "Sweep Time"on page 63), those values are
also predefined. For each sweep point with a frequency under 10 MHz in the table,
suitable settings are defined. For higher frequencies, the values provided in the measurement settings are used (indicated by "--" as they are automatically updated if the
measurement settings change.) All predefined values in the table can be overwritten
manually.
See also "Variable RBW and sweep time for low-frequency measurements"
on page 35.
Remote command:
[SENSe:]FREQuency:TABLe:DATA on page 106
[SENSe:]FREQuency:LIST:DATA on page 107
RBW and sweep time set to variable: [SENSe:]BANDwidth:LIST:DATA
on page 107
Insert
Inserts a new measurement point above the one you have selected.
Delete
Deletes the currently selected measurement point.
Import / Export
Opens a dialog box to select a frequency table to import or export.
An import copies the frequency table into the default frequency table directory. An
export copies the table to a location outside the default frequency table directory, e.g. a
memory stick. The file extension has to be *.freq.
If variable RBW and sweep times are enabled, they are also included in a table export
(see "Frequency Table"on page 46).
For details on the required file format, see Chapter A, "Reference: frequency table file
format", on page 185.
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5.3Selecting DUT characteristics
Configuration
Selecting DUT characteristics
Access: "Overview" > "DUT" > "DUT Settings"
The "DUT" button opens a dialog box to configure the characteristics of the DUT you
are testing. The dialog box contains a schematic overview of the DUT input and output
characteristics and the way it is integrated into the test setup.
Defines a fixed LO frequency for measurements on frequency-converting DUTs with a
fixed LO.
After you have defined the LO frequency, the application updates the frequency list
accordingly.
The "LO" setting is also available via the [FREQ] key.
Remote command:
[SENSe:]CONFigure:MODE:SYSTem:LO:FREQuency on page 110
Image Rejection
Turns image rejection of the DUT on and off.
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5.4Configuring the noise source
Configuration
Configuring the noise source
If you set an image rejection of 0 dB, the image frequency passes completely. If you
set a high image rejection (up to 999.99 dB), the image frequency is suppressed completely. For DUTs that have a partial image rejection, define the amount of suppression.
For more information, see Chapter 4.4, "Image frequency rejection", on page 28.
Remote command:
[SENSe:]CORRection:IREJection on page 111
The noise source characteristics are used to calculate the effective "noise temperature"
of the noise source. The more accurate the specified characteristics of the noise
source you are using, the more accurate the measurement results. The noise source
characteristics must be supplied by its manufacturer.
●Defining the noise source characteristics................................................................49
●Using an ENR or temperature table........................................................................53
The noise characteristics of noise sources with diode characteristics are usually
defined by their ENR (Excess Noise Ratio). The noise characteristics of noise sources
with resistor characteristics are defined by their noise (or ambient) temperatures (T
and T
Both noise source types can have different ENR values during the calibration and the
measurement stage. You can use either the same type of noise source for both calibration and measurement, or use different types of noise sources for calibration and measurement.
cold
). T
is typically at a very low temperature of liquid nitrogen or liquid helium.
cold
hot
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Configuration
Configuring the noise source
Auto Select SNS........................................................................................................... 50
If enabled (default), the R&S FPL1 Noise Figure measurements application automatically recognizes a connected smart noise source and uses it for the noise measurement. The provided ENR and uncertainty tables and temperature are loaded and used
for the measurement. The recognized serial number of the SNS is indicated in the
channel bar and dialogs of the R&S FPL1 Noise Figure measurements application.
If "Auto Select SNS" is ON and a SNS is connected, a green message with information
about the connected SNS is displayed:
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Configuration
Configuring the noise source
If no SNS is connected, a red "No SNS connected" warning is displayed:
If "Auto Select SNS" is disabled, you must manually change the noise source to SNS
and select the required tables, if necessary (see "Frequency Table"on page 46).
You can select the type of noise source and its characteristics independently for the
Calibration and the Measurement.
"Diode"
Selects a noise source with diode characteristics. The frequency
characteristics of the noise source are defined by the Excess Noise
ratio (ENR).
"Resistor"
Selects a test setup that uses two resistors which act as a noise
source. One of the resistors has a low noise or ambient temperature
(a cold resistor), the other has a high noise or ambient temperature (a
hot resistor). The noise characteristics of the resistor are defined by
its "noise temperatures" T
and T
hot
cold
.
When you select the resistor noise source, the application automatically starts the manual measurement mode, which is indicated in a
message at the bottom of the dialog box.
"Smart Noise
Source"
Selects a smart noise source, which provides its own ENR and uncertainty tables. The serial number of the connected noise source is
automatically recognized and indicated. Otherwise, enter the number
of a noise source to continue preconfiguring the measurement.
[SENSe:]CORRection:ENR:CALibration:SNS:SRNumber on page 119
Measurement
Selects the source of the ENR or temperature values.
The frequency characteristics can be approximated by a constant or be based on an
ENR or temperature table.
If the ENR or temperature is a constant, the same values are used for all frequencies
in the frequency table. If you have selected a constant ENR, you have to define its
magnitude in the input field next to the radio button. If you have selected a constant
temperature, you have to define the temperatures of the resistor in the input fields next
to the radio button. T
temperature; T
cold
is the temperature of a resistor with a low noise or ambient
hot
is the temperature of a resistor with a high noise or ambient temper-
ature.
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Configuration
Configuring the noise source
If the noise characteristics are based on a table, the ENR level and temperatures typically depend on the measurement frequency. You can select an existing table from the
dropdown menu next to the radio button, if it is active. For more information on ENR
and temperature tables, see Chapter 5.4.2, "Using an ENR or temperature table",
on page 53.
When "Common Noise Source" is on, the ENR is used for both measurement and calibration.
Remote command:
ENR mode: [SENSe:]CORRection:ENR[:MEASurement]:MODEon page 117
Constant ENR: [SENSe:]CORRection:ENR[:MEASurement]:SPOTon page 117
Select table:[SENSe:]CORRection:ENR[:MEASurement]:TABLe:SELect
on page 115
Constant temperature: [SENSe:]CORRection:ENR[:MEASurement]:SPOT:COLD
on page 118
Constant temperature: [SENSe:]CORRection:ENR[:MEASurement]:SPOT:HOT
on page 118
Common Noise Source
Turns the use of a common ENR on and off.
Common ENRs have the same characteristics for the measurement and calibration. If
you turn off common ENR, you can define an additional ENR to be used during calibration.
Define additional ENR for measurements on frequency converting DUTs, if one noise
source does not cover the frequency range at the DUT input (RF) and for calibration
(IF).
Remote command:
[SENSe:]CORRection:ENR:COMMon on page 114
Calibration
Selects the source of the ENR or temperature values used during calibration.
The frequency characteristics can be a constant or be based on an ENR or tempera-
ture table.
If the ENR or temperature is a constant, the same value is used for all frequencies in
the frequency table. If you have selected a constant ENR, you can also define its value
in the input field next to the radio button. If you have selected a constant temperature,
you have to define the temperatures of the resistor in the input fields next to the radio
button. T
T
is the temperature of a resistor with a high noise or ambient temperature.
cold
is the temperature of a resistor with a low noise or ambient temperature;
hot
If the noise source characteristics are based on a table, the ENR level and temperature
depend on the measurement frequency. In that case, the values are interpolated to the
measurement points. You can select a table from the dropdown menu next to the radio
button, if it is active. For more information on ENR tables, see Chapter 5.4.2, "Using an
ENR or temperature table", on page 53.
The calibration settings are available if the "Common Noise Source" is off.
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Configuration
Configuring the noise source
Remote command:
ENR mode:[SENSe:]CORRection:ENR:CALibration:MODEon page 112
Constant ENR: [SENSe:]CORRection:ENR:CALibration:SPOTon page 113
Select table: [SENSe:]CORRection:ENR:CALibration:TABLe:SELect
on page 113
Constant temperature: [SENSe:]CORRection:ENR:CALibration:SPOT:COLD
on page 112
Constant temperature: [SENSe:]CORRection:ENR:CALibration:SPOT:HOT
on page 112
Temperature
Defines the absolute room temperature in degree Celsius or Fahrenheit.
The room temperature is required for the calculation of the real ENR of the noise
source, because an ENR table is based on a temperature of 290K.
For smart noise sources, the temperature is provided automatically by the connected
SNS itself. If no SNS is connected, the most recently loaded value is indicated. The
provided temperature is used for all noise sources throughout the measurement.
To change the unit of the temperature from Celsius to Fahrenheit, change the date format from "DE" to "US" in the "General" display settings.
●
Press the [SETUP] key.
●
Select "Display".
●
Select the "General" tab.
●
Select "DE" for Celsius or "US" for Fahrenheit.
Note: If you define the temperature via remote control, the unit is degree Kelvin.
Remote command:
The "Table Settings" tab in the "ENR/TEMP Settings" dialog box contains the functionality to create and edit ENR or temperature tables.
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Configuration
Configuring the noise source
ENR or temperature tables contain the noise source characteristics for particular frequencies. If the table does not contain ENR or temperature values for one of the measurement frequencies, the application interpolates between the values.
The "Table Settings" tab contains a list of ENR and temperature tables currently available on the R&S FPL1000 and shows the table currently in use if the "ENR/TEMP Settings" are enabled.
In addition, the tab contains functionality to create new tables and modify existing
ones.
Selects the type of noise source you are using for the measurement. The type of noise
source selected in the "ENR/TEMP Settings" > "Noise Source" dialog is adopted automatically.
The noise source type affects the data type that the table contains. For a "Noise
Diode", the table contains the ENR values of the noise source you are using. For a
"Resistor", the table contains the "noise temperatures" of the resistors (T
and T
hot
cold
).
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Configuration
Configuring the noise source
For a smart noise source, the table contains the provided ENR and uncertainty table.
The table for the connected noise source is automatically recognized and highlighted.
The name of the ENR table contains the serial number of the SNS. The "default" table
also contains the data for the most recently connected smart noise source. The tables
for all previously connected noise sources, whose ENR tables remain stored on the
instrument, are also listed. Smart noise source tables are for reference only and cannot
be edited.
For more information on the noise source types, see "Noise Source"on page 51.
Remote command:
[SENSe:]CORRection:ENR[:MEASurement]:TYPE on page 117
New
Opens the Edit Table dialog box to create a new table.
The contents of the dialog box are empty.
Smart noise source tables are shown for reference only and cannot be edited. A mes-
sage indicates whether the SNS with the selected serial number is currently connected
to the R&S FPL1000 or not. If it is connected, the table data reflects the most recent
data provided by the SNS.
Opens the Edit Table dialog box to modify the selected table and save it under a new
name.
Import / Export Table
Opens a dialog box to select a table to import or export.
Smart noise source tables can be exported, but not re-imported. Tables for smart noise
sources are always loaded directly from the SNS itself. However, you can edit and use
the SNS tables for other noise sources, such as noise diodes.
Edit Table
Defines the noise source characteristics or the loss characteristics of additional measurement equipment.
The noise source and loss tables are made up of up to 10001 data points. A data point
consists of a frequency and its corresponding ENR, temperature or loss value. The
ENR and temperature values must be supplied by the manufacturer of the noise
source or resistor. The loss characteristics of measurement equipment must also be
supplied by the manufacturer.
"Name"
"Comment"
"Frequency"
Name of the ENR, temperature or loss table.
Comment for the ENR, temperature or loss table.
Frequency of a particular ENR, temperature or loss value.
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Configuration
Configuring additional loss
"Value"
"Clear Table"
"Insert"
"Delete"
"Save"
"Cancel"
Remote command:
Edit ENR table: [SENSe:]CORRection:ENR[:MEASurement]:TABLe[:DATA]
on page 114
Edit temperature table: [SENSe:]CORRection:ENR[:MEASurement]:TABLe:
TEMPerature[:DATA] on page 116
Edit input loss table: [SENSe:]CORRection:LOSS:INPut:TABLe[:DATA]
on page 122
Edit output loss table: [SENSe:]CORRection:LOSS:OUTPut:TABLe[:DATA]
on page 125
ENR value or loss in dB.
For a resistor, the characteristics of the resistor are defined by the
"noise temperatures" T
in that case is Kelvin (degrees).
Deletes the contents of the table (frequencies and values) or the loss
table.
Inserts a new data point above the selected one.
Deletes the selected data point.
Saves the able.
Exits the "Edit Table" dialog box and returns to the result diagram.
and T
hot
instead of a single value. The unit
cold
5.5Configuring additional loss
These settings configure the loss characteristics of additional equipment in the test
setup, such as cables or attenuators at the DUT input or output. The characteristics of
such equipment must be supplied by the manufacturer.
Note that loss is only considered during the measurement and not during calibration
because the noise source is connected directly to the analyzer input.
Treatment of losses in resistor noise sources
For resistor noise sources, it is not possible to change the loss characteristics.
When you change back to using a diode as a noise source, the previous loss settings
are not restored. In that case, store loss settings in a loss table for later use.
The "Loss Settings" tab in the "Loss Settings" dialog box contains settings to define the
loss characteristics of miscellaneous equipment in the test setup.
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Configuration
Configuring additional loss
You can define the loss characteristics of the signal path to the DUT input and the signal path from the DUT output to the analyzer.
Furthermore, you can define the loss characteristics of the signal path from the noise
source directly to the analyzer for the calibration measurement.
Defines losses between the noise source and the DUT input.
The input loss is the sum of all losses caused by the measurement equipment. The
loss can be constant or based on a loss table.
If the loss is constant, the same loss is used for all frequencies in the frequency table.
If you have selected a constant loss, you can also define its value in the input field next
to the radio button.
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Configuration
Configuring additional loss
If the loss is based on a table, the loss values are interpolated to the measurement frequencies. You can select a table from the dropdown menu next to the radio button, if it
is active. For more information on loss tables, see Chapter 5.5.2, "Using a loss table",
on page 60.
The specified temperature at the time of measurement can be considered in the loss
calculation.
Remote command:
Loss mode:
[SENSe:]CORRection:LOSS:INPut:MODE on page 122
Constant loss:
[SENSe:]CORRection:LOSS:INPut:SPOT on page 122
Select loss table:
[SENSe:]CORRection:LOSS:INPut:TABLe:SELect on page 123
Temperature:
[SENSe:]CORRection:LOSS:INPut:TEMPerature on page 124
Output Loss
Selects the loss between the DUT output and the RF input of the analyzer.
The output loss is the sum of all losses caused by the measurement equipment (e.g.
connectors, cables or attenuators). The loss can be constant or be based on a loss
table.
If the loss is constant, the same loss is used for all frequencies in the frequency table.
If you have selected a constant loss, you can also define its value in the input field next
to the radio button.
If the loss is based on a table, the loss values are interpolated to the measurement frequencies. You can select a table from the dropdown menu next to the radio button, if it
is active. For more information on loss tables, see Chapter 5.5.2, "Using a loss table",
on page 60.
The current temperature at the time of measurement can be considered in the loss calculation.
Remote command:
Loss mode:
[SENSe:]CORRection:LOSS:OUTPut:MODE on page 124
Constant loss:
[SENSe:]CORRection:LOSS:OUTPut:SPOT on page 124
Select loss table:
[SENSe:]CORRection:LOSS:OUTPut:TABLe:SELect on page 125
Temperature:
[SENSe:]CORRection:LOSS:OUTPut:TEMPerature on page 126
Calibration Loss
Selects the loss between the noise source and the RF input of the analyzer for the calibration measurement.
The loss is the sum of all losses caused by the measurement equipment (e.g. connectors, cables or attenuators). The loss can be constant or be based on a loss table.
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Configuration
Configuring additional loss
If the loss is constant, the same loss is used for all frequencies in the frequency table.
If you have selected a constant loss, you can also define its value in the input field next
to the radio button.
If the loss is based on a table, the loss values are interpolated to the measurement frequencies. You can select a table from the dropdown menu next to the radio button, if it
is active. For more information on loss tables, see Chapter 5.5.2, "Using a loss table",
on page 60.
The current temperature at the time of measurement can be considered in the loss calculation.
Remote command:
Loss mode:
[SENSe:]CORRection:LOSS:CALibration:MODE on page 120
Constant loss:
[SENSe:]CORRection:LOSS:CALibration:SPOT on page 120
Select loss table:
[SENSe:]CORRection:LOSS:CALibration:TABLe:SELect on page 121
Temperature:
[SENSe:]CORRection:LOSS:CALibration:TEMPerature on page 122
The "Table Settings" tab in the "Loss Settings" dialog box contains the functionality to
create and edit loss tables.
Loss tables contain the loss characteristics of additional frequency-dependent equipment in the test setup. If you are using a loss table, the loss values can be different on
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Configuration
Configuring additional loss
each frequency that is measured. If the table does not contain a loss for one of the
measurement frequencies, the application interpolates between values.
The "Table Settings" tab contains a list of loss tables currently available on the
R&S FPL1000. It shows the table currently selected in the "Loss Settings" tab.
In addition, the tab contains functionality to create new tables and modify existing
ones.
Opens the Edit Table dialog box to create a new loss table.
The contents of the dialog box are empty.
Remote command:
Create input loss table:
[SENSe:]CORRection:LOSS:INPut:TABLe[:DATA] on page 122
Create output loss table:
[SENSe:]CORRection:LOSS:OUTPut:TABLe[:DATA] on page 125
Create calibration loss table:
[SENSe:]CORRection:LOSS:CALibration:TABLe[:DATA] on page 121
Edit
Opens the Edit Table dialog box to modify the selected table.
Remote command:
Edit input loss table:
[SENSe:]CORRection:LOSS:INPut:TABLe[:DATA] on page 122
Edit output loss table:
[SENSe:]CORRection:LOSS:OUTPut:TABLe[:DATA] on page 125
Edit calibration loss table:
[SENSe:]CORRection:LOSS:CALibration:TABLe[:DATA] on page 121
Delete
Deletes the selected table.
Remote command:
Delete input loss table:
[SENSe:]CORRection:LOSS:INPut:TABLe:DELete on page 123
Delete output loss table:
[SENSe:]CORRection:LOSS:OUTPut:TABLe:DELete on page 125
Delete calibration loss table:
[SENSe:]CORRection:LOSS:CALibration:TABLe:DELete on page 120
Copy To
Opens the Edit Table dialog box to modify the selected table and save it under a new
name.
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5.6Configuring the analyzer
Configuration
Configuring the analyzer
Import / Export Table
Opens a dialog box to select a loss table to import or export.
An import copies the loss table into the default loss table directory. The file extension
can be *.loss or *.s2p. In case the file extension is *.s2p, the S21 vector is parsed
out of the *.s2p file. The magnitude of this vector is written to a file with ending
*.loss into the default loss directory. This file then can be used like conventional loss
files.
An export copies the table to a location outside the default loss table directory, e.g. a
memory stick. The file extension will be *.loss.
Access: "Overview" > "Spectrum Analyzer"
Or: [MEAS CONFIG] > "Meas Settings"
The measurement settings include parameters related to the second stage correction
measurement.
Defines the resolution bandwidth for the measurement.
For more information on the resolution bandwidth, see Chapter 4.7, "Separating sig-
nals by selecting an appropriate resolution bandwidth", on page 35.
"Constant"
"Variable"
Remote command:
[SENSe:]BANDwidth:RESolution:AUTO on page 127
[SENSe:]BANDwidth[:RESolution] on page 126
Uses a constant RBW for the entire measurement span
Uses a variable RBW, depending on the current frequency of the
sweep point, as defined in the frequency table (see Chapter 5.2.3,
"Using a frequency table", on page 45);
In the channel bar, the bandwidth and sweep time range of the variable values is indicated.
Sweep Time
Defines the sweep time for the measurement.
The sweep time is the time it takes the analyzer to perform a measurement at one
measurement frequency.
Note that "noise figure" measurements perform two measurements during one sweep.
One with the noise source turned on, one with the noise source turned off.
Frequency tables allow you to define a variable RBW and sweep time, depending on
the current frequency of the sweep point (see "Variable RBW and sweep time for low-
frequency measurements"on page 35 and Chapter 5.2.3, "Using a frequency table",
on page 45).
"Constant"
Uses a constant sweep time for the entire measurement span
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Configuration
Configuring the analyzer
"Variable"
Remote command:
[SENSe:]SWEep:TIME:AUTO on page 129
[SENSe:]SWEep:TIME on page 129
Settling Time
Defines the settling time of the DUT and the noise source.
Most noise sources need a certain amount of time to settle after you turn them on.
Low-frequency DUTs can require a certain time until their coupling capacitors have
been charged or discharged. Both are defined as the settling time. For details on the
settling time, refer to the datasheet of the noise source.
Remote command:
SYSTem:CONFigure:DUT:STIMe on page 132
Average
Defines the number of measurements that are used to average the results.
The more measurements you include in the averaging, the more accurate and stable
the results are. However, accuracy and stability come at the price of measurement
speed.
Remote command:
[SENSe:]SWEep:COUNt on page 129
Uses a variable sweep time, depending on the current frequency of
the sweep point, as defined in the frequency table (see Chapter 5.2.3,
"Using a frequency table", on page 45);
In the channel bar, the bandwidth and sweep time range of the variable values is indicated.
Ref Level
Turns automatic determination of the reference level on and off.
The reference level is the power level the R&S FPL1000 expects at the RF input. Keep
in mind that the noise signal has a high crest factor. To avoid an instrument overload,
set the reference level to the peak envelope power of the noise signal, not to the mean
power.
Set the reference level to approximately 5 dB to 15 dB above the noise display that
occurs with the DUT connected and the noise source activated.
To get the best dynamic range, set the reference level as low as possible. At the same
time, make sure that the maximum signal level does not exceed the reference level. If
it does, it can overload the RF and IF stages of the analyzer, regardless of the signal
power. Measurement results can deteriorate.
Note that the signal level at the A/D converter can be stronger than the level the
R&S FPL1000 displays because the resolution bandwidths are implemented digitally
after the A/D converter.
If automatic detection of the reference level is on, the application performs a measurement to determine the ideal reference level. The time of this measurement depends on
the state of the "2nd Stage Correction".
●
"2nd Stage Correction" is enabled
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Configuration
Configuring the analyzer
The application determines the reference level before the calibration starts. The
reference level is based on several test measurements on the start frequency.
For more information, see "Auto Level Range"on page 65.
●
"2nd Stage Correction" is disabled
The application determines the reference level before the measurement begins.
The reference level is based on the measurement of the first frequency that is
measured. After this measurement is done, the application resumes the measurement.
If manual selection of the reference level is on, you can define the reference level in
the corresponding input field.
Note: Reference level. Even for DUTs with a high-ripple frequency response it can be
useful to define the reference level manually. Determining the reference level automatically does not always result in optimal settings.
Remote command:
Manual reference level:
DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:RLEVel on page 130
Automatic reference level:
DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:RLEVel:AUTO on page 130
Auto Level Range
Defines the maximum expected "gain" of the DUT.
The application uses the auto level range to determine the reference level automati-
cally if the 2nd stage correction is on.
Make sure the range does not exceed the actual "gain" of the DUT by more than
10 dB.
Remote command:
SYSTem:CONFigure:DUT:GAIN on page 132
RF Attenuation
Defines the RF attenuation of the analyzer.
The attenuation is applied to the signal at the RF input.
Attenuation affects the quality of the "noise figure" measurement results. For a low
"noise figure" of the analyzer (and thus more accurate measurement results), keep the
attenuation as low as possible. No attenuation is best. However, some high-power
DUTs require attenuation to avoid an overload of the analyzer. An attenuation of 10 dB
provides a better input VSWR of the analyzer, but results in a deteriorating "noise figure".
Remote command:
INPut<ip>:ATTenuation on page 130
Preamplifier
If the (optional) internal preamplifier hardware is installed, a preamplifier can be activated for the RF input signal.
Turn on the preamplifier for a low inherent noise of the analyzer.
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5.7Using the uncertainty calculator
Configuration
Using the uncertainty calculator
Note: If an optional external preamplifier is activated, the internal preamplifier is automatically disabled, and vice versa.
The input signal is amplified by 20 dB if the preamplifier option is activated.
Remote command:
INPut<ip>:GAIN:STATe on page 131
Access: [MEAS CONFIG] > "Uncertainty Calculation"
"Noise figure" measurements are subject to uncertainty. The "noise figure" measurement is meaningless if the measurement uncertainty is too large. Knowing the uncertainty of the "noise figure" measurement adds value especially when comparing measurement results.
Note that the "noise figure" uncertainty is not calculated for frequencies above 67 GHz
because input VSWR values are not specified.
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Configuration
Using the uncertainty calculator
Uncertainty values and systematic error recognition
Note that the uncertainty calculation only takes systematic measurement inaccuracies
into account.
The most significant inaccuracies are:
●
Uncertainties of the noise source and the analyzer
●
Input and output matching
●
"Noise figure" and "gain" of the DUT
●
"Noise figure" of the analyzer
The accuracy of the measurement can also be affected by insufficient repeatability during calibration or measurement.
The repeatability is mainly affected by:
●
Signal-to-noise ratio during calibration and measurement
●
Measurement time (if it is too short)
●
Environmental conditions (e.g. a change in the temperature between measurements)
●
Mechanical stability of the test setup
For more background information on "noise figure" measurement uncertainty, refer to
the application note "The "Y-Factor" Technique for "Noise Figure" Measurement" available for download on the Rohde & Schwarz homepage (http://www.rohde-
In addition to the parameters described here, the application also considers several
parameters from the general measurement configuration when calculating the uncertainty.
●
Measurement mode
●
2nd Stage Correction
If 2nd stage correction is on, but no calibration data is available, uncertainty is calculated without the 2nd stage correction data.
●
RF Attenuation
●
Temperature
●
ENR values
5.7.1Configuring noise source characteristics
Access: [MEAS CONFIG] > "Uncertainty Calculation"
The Uncertainty Calculator supports individual characteristics for a noise source used
during calibration and the measurement.
If you are using a Common ENR, the application assumes that the Output Match and
ENR Uncert(ainty) are the same during calibration and measurement. Only the "Mea-
surement Noise Source" parameters are displayed.
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Configuration
Using the uncertainty calculator
If you are using a different noise source during calibration and measurement, the
Uncertainty Calculator adds an Output Match and ENR Uncert(ainty) required for
uncertainty calculation during calibration.
Note that you have to turn off the Common Noise Source if you have to define the values of the noise source used during calibration.
Common Source for Meas and Cal...............................................................................68
Use SNS Values............................................................................................................68
Temperature Uncert(ainty)............................................................................................ 69
Common Source for Meas and Cal
Controls the way the application calculates the uncertainty for the noise source.
Turn on the switch when you use the same noise source during calibration and mea-
surement. Only one set of fields to define the noise source characteristics is available.
The application calculates the uncertainty according to the values you have entered in
there.
Turn the switch off when you use different noise sources during calibration and measurement. The application shows an additional set of fields to define the noise source
characteristics. The uncertainty calculation also includes these values.
The switch is available if you have turned on Common Noise Source.
Remote command:
CALCulate<n>:UNCertainty:COMMon on page 133
Use SNS Values
If enabled, the values from the uncertainty table provided by the (most recently) connected smart noise source are used.
Output Match
Defines the output match of the noise source you are using.
You can define the output match either as the VSWR or as the return loss (RL).
Refer to the datasheet of the noise source for these values.
If a smart noise source is used, the VSWR / RL values defined in the SNS table are
used.
Remote command:
CALCulate<n>:UNCertainty:MATCh:SOURce:CALibration:RL on page 139
CALCulate<n>:UNCertainty:MATCh:SOURce:RL on page 139
CALCulate<n>:UNCertainty:MATCh:SOURce:CALibration[:VSWR]
on page 139
CALCulate<n>:UNCertainty:MATCh:SOURce:CALibration:RL on page 139
ENR Uncert(ainty)
Defines the uncertainty of the excess noise ratio of the noise source you are using.
Refer to the datasheet of the noise source for this value.
Available for noise sources with diode characteristics.
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Configuration
Using the uncertainty calculator
If a smart noise source is used, the ENR uncertainty values defined in the SNS table
are used.
Remote command:
CALCulate<n>:UNCertainty:ENR:UNCertainty on page 136
CALCulate<n>:UNCertainty:ENR:CALibration:UNCertainty on page 135
Temperature Uncert(ainty)
Defines the uncertainty of the hot and cold temperatures of the noise source you are
using.
Refer to the datasheet of the noise source for these values.
Available for resistor noise sources.
Remote command:
CALCulate<n>:UNCertainty:ENR:UNCertainty:COLD on page 136
CALCulate<n>:UNCertainty:ENR:CALibration:UNCertainty:HOT
Use Measurement Values............................................................................................. 69
Input / Output Match
Defines the match at the DUT input and output.
You can define the match either as the VSWR or as the return loss (RL). If you define
the VSWR or the return loss, the application automatically calculates the other.
If these values are not defined in the DUT datasheet, determine these values, for
example, with a network analyzer.
Remote command:
CALCulate<n>:UNCertainty:MATCh:DUT:IN[:VSWR] on page 137
CALCulate<n>:UNCertainty:MATCh:DUT:IN:RL on page 137
CALCulate<n>:UNCertainty:MATCh:DUT:OUT[:VSWR] on page 138
CALCulate<n>:UNCertainty:MATCh:DUT:OUT:RL on page 138
Use Measurement Values
Turns automatic determination of the DUT characteristics used for the uncertainty calculation on and off.
If on, the application calculates the uncertainty with the DUT characteristics ("noise figure", "gain" and frequency) resulting from the "noise figure" measurement. For this
method, the application calculates the uncertainty for each measurement point (or frequency) based on the "noise figure" and "gain" results of the last measurement.
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Configuration
Using the uncertainty calculator
If you have selected automatic determination of the DUT characteristics, the application does not show a result in the "NF Uncertainty +/-" field in the dialog box. Instead,
to view the uncertainty at all measurement points, use the "Result Table".
If off, define the "gain", "noise figure" and frequency of the DUT manually for a single
frequency. With this manual determination of the DUT characteristics, the application
only calculates the uncertainty for that frequency and shows the result in the "NF
Uncertainty +/-" field in the dialog box.
●
"Noise Figure" of the DUT
●
"Gain" of the DUT
●
Frequency of the DUT
Remote command:
Control automatic DUT characteristics determination:
CALCulate<n>:UNCertainty[:RESult]? on page 141
Manual definition of DUT characteristics:
CALCulate<n>:UNCertainty:DATA:NOISe on page 134
CALCulate<n>:UNCertainty:DATA:GAIN on page 134
CALCulate<n>:UNCertainty:DATA:FREQuency on page 133
5.7.3Configuring analyzer characteristics
Access: [MEAS CONFIG] > "Uncertainty Calculation"
For the analyzer characteristics, the application always uses the data specified in the
datasheet of the R&S FPL1000 model you are using. Thus, it is not possible to change
or adjust the analyzer characteristics in any way. The uncertainty calculation takes several analyzer characteristics into account, of which the following are shown as readonly fields in the user interface.
●
SA Input Match: Input match (VSWR or return loss) of the analyzer
●
SA NF Uncert: "Noise figure" uncertainty of the analyzer
●
SA "Gain" Uncert: "Gain" uncertainty of the analyzer
●
SA NF: "Noise figure" of the analyzer
However, if you are using an external preamplifier in the test setup, you have to specify
its characteristics to get a valid uncertainty result.
Remote commands:
CALCulate<n>:UNCertainty:SANalyzer:GAIN:UNCertainty? on page 142
CALCulate<n>:UNCertainty:SANalyzer:NOISe:UNCertainty? on page 142
└ Preamplifier Gain (PA Gain)............................................................................71
└ Net spectrum analyzer noise figure (Net SA NF)............................................71
External Preamplifier (Ext PA)
If enabled, the application automatically calculates and updates the analyzer characteristics based on the characteristics of the external preamplifier defined here.
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Configuration
Using the uncertainty calculator
Refer to the datasheet of the preamplifier you are using for the values you have to
enter.
Defines the "noise figure" of the preamplifier.
Remote command:
CALCulate<n>:UNCertainty:PREamp:NOISe on page 140
Preamplifier Gain (PA Gain) ← External Preamplifier (Ext PA)
Defines the "gain" of the preamplifier.
Remote command:
CALCulate<n>:UNCertainty:PREamp:GAIN on page 140
Net spectrum analyzer noise figure (Net SA NF) ← External Preamplifier (Ext PA)
Shows the "noise figure" of the analyzer.
If you are using an external preamplifier, the application calculates the "noise figure" of
the analyzer including the "noise figure" of the preamplifier and shows the result here.
If you do not use an external preamplifier, this value is the same as the "noise figure" of
the analyzer shown in the "SA NF" field.
5.7.4Guidelines and results
Access: [MEAS CONFIG] > "Uncertainty Calculation"
The lower part of the dialog box contains measurement guidelines that provide information on the quality of measurement and the actual "noise figure" uncertainty.
Guidelines
The guidelines are an indicator of the quality of the measurement and an indicator the
repeatability of the measurement.
The three guidelines are:
●
Make sure that the "noise figure" of the DUT and the "gain" of the DUT is greater
than the "noise figure" of the analyzer plus 1 dB.
●
Make sure that the ENR of the noise source is greater than the "noise figure" of the
DUT plus 5 dB.
●
Make sure that the ENR of the noise source is greater than the "noise figure" of the
analyzer plus 3 dB.
A short form of these guidelines is indicated in the "Uncertainty Calculation" dialog box.
The dialog box also indicates if the guidelines have been met or not by a colored dot.
●
Green light
●
Yellow light : guideline condition not met, but within 1dB of being met.
●
Red light : guideline condition not met.
: guideline condition met.
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Performing measurements
Note that the guidelines have no effect on the actual uncertainty that has been calculated and that they are only considered for measurements with 2nd Stage Correction.
Uncertainty
The "Uncertainty" result is shown only if you define the "noise figure" and "gain" characteristics of the DUT manually on a single frequency. In that case, the uncertainty
shown in the "Uncertainty Calculation" dialog box is valid only for the DUT frequency
you have defined.
The "Measurement Offset" evaluates the internal noise of the R&S FPL1000 that is
added to the "noise figure" results. The measurement offset result is displayed when
2nd stage correction is turned off. When you turn on 2nd stage correction, the internal
noise is automatically removed from the uncertainty results, so the measurement offset
is not shown.
If you are using the "noise figure" and "gain" that has been determined during a measurement, the uncertainty is displayed only in the result table.
For more information, see "Use Measurement Values"on page 69.
SCPI command:
CALCulate<n>:UNCertainty[:RESult]? on page 141
5.8Performing measurements
Access: [SWEEP]
Access (calibration): "Overview" > "Calibrate"
This chapter contains all functionality necessary to control and perform "noise figure"
measurements.
Continuous Sweep / Run Cont......................................................................................72
Single Sweep / Run Single............................................................................................73
After triggering, starts the measurement and repeats it continuously until stopped.
Initiates a measurement and repeats it continuously until stopped. If necessary, the
application automatically determines the reference level before starting the actual measurement.
While the measurement is running, the "Continuous Sweep" softkey and the [RUN
CONT] key are highlighted. The running measurement can be aborted by selecting the
highlighted softkey or key again. The results are not deleted until a new measurement
is started.
Note: Sequencer. If the Sequencer is active, the "Continuous Sweep" softkey only controls the sweep mode for the currently selected channel setup. However, the sweep
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Configuration
Performing measurements
mode only takes effect the next time the Sequencer activates that channel setup, and
only for a channel-defined sequence. In this case, a channel setup in continuous
sweep mode is swept repeatedly.
Furthermore, the [RUN CONT] key controls the Sequencer, not individual sweeps.
[RUN CONT] starts the Sequencer in continuous mode.
For details on the Sequencer, see the R&S FPL1000 User Manual.
Remote command:
INITiate<n>:CONTinuous on page 143
Single Sweep / Run Single
Initiates a single measurement. The measurement is finished after all frequencies in
the frequency list have been measured. If necessary, the application automatically
determines the reference level before starting the actual measurement.
After triggering, initiates a single measurement. The measurement is finished after all
frequencies in the frequency list have been measured. If necessary, the application
automatically determines the reference level before starting the actual measurement.
While the measurement is running, the "Single Sweep" softkey and the [RUN SINGLE]
key are highlighted. The running measurement can be aborted by selecting the highlighted softkey or key again.
Note: Sequencer. If the Sequencer is active, the "Single Sweep" softkey only controls
the sweep mode for the currently selected channel setup. However, the sweep mode
only takes effect the next time the Sequencer activates that channel setup, and only for
a channel-defined sequence. In this case, the Sequencer sweeps a channel setup in
single sweep mode only once.
Furthermore, the [RUN SINGLE] key controls the Sequencer, not individual sweeps.
[RUN SINGLE] starts the Sequencer in single mode.
If the Sequencer is off, only the evaluation for the currently displayed channel setup is
updated.
For details on the Sequencer, see the R&S FPL1000 User Manual.
Remote command:
INITiate<n>[:IMMediate] on page 144
Calibrate
Initiates a calibration measurement.
For interpolation purposes, R&S FPL1000-K30 will internally add addiitonal measure-
ment points at the band switching frequencies. This may increase the time needed to
complete the calibration.
For more information see Chapter 4.5, "Calibration (2nd stage correction)",
on page 31.
Remote command:
INITiate<n>[:IMMediate] on page 144
when [SENSe:]CONFigure:CORRection is on.
Sweep Time
Defines the sweep time.
For more information see "Sweep Time"on page 63.
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5.9Configuring inputs and outputs of the R&S FPL1000
Configuration
Configuring inputs and outputs of the R&S FPL1000
Meas Mode (Auto Manual)
Selects the measurement mode for the hot and cold power measurements.
For more information about the measurement modes see Chapter 4.2, "Measurement
modes", on page 25.
In manual measurement mode, the application opens a dialog box when you start a
measurement. For more information about its contents see "Performing a manual mea-
surement"on page 26.
Remote command:
[SENSe:]CONFigure:CONTrol on page 145
[SENSe:]CONFigure:MEASurement on page 146
The only input setting available for the R&S FPL1 Noise Figure measurements application on the R&S FPL1000 is Chapter 5.9.1, "Impedance", on page 74.
In addition, the optional independent CW source (R&S FPL1000-K14 option) is supported. See the R&S FPL1000 user manual.
For some measurements, the reference impedance for the measured levels of the
R&S FPL1000 can be set to 50 Ω or 75 Ω.
Select 75 Ω if the 50 Ω input impedance is transformed to a higher impedance using a
75 Ω adapter of the RAZ type. (That corresponds to 25Ω in series to the input impedance of the instrument.) The correction value in this case is 1.76 dB = 10 log (75Ω/
50Ω).
Remote command:
INPut<ip>:IMPedance on page 147
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6Analysis
6.1Configuring the display
Analysis
Configuring the display
This chapter contains all settings and parameters that the application provides to analyze and evaluate measurement results.
●Configuring the display............................................................................................75
●Working with traces.................................................................................................78
Display configuration settings configure the way the results are displayed in the diagram.
The contents depend on whether you want to configure a graphical result display or a
numerical result display.
Specifics for
The settings you make apply to the results you have selected in the "Specifics for"
dropdown menu. If more than one window is active, "Specifics for" also puts the focus
on the corresponding window.
Selects the result display and thus the scaling of the vertical axis.
For more information, see Chapter 3, "Measurements and result displays", on page 14.
Auto Scale / Min / Max
Turns automatic scaling of the vertical axis on and off.
If on, the application optimizes the scaling of the vertical axis after each measurement
for ideal viewing of the results.
If off, you can define the scaling manually. The "Min" and "Max" input fields become
available. These two input fields define the values at the top and bottom of the vertical
axis.
Remote command:
Automatic scaling:
DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:AUTO on page 151
Manual minimum value:
DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:BOTTom on page 151
Manual maximum value
DISPlay[:WINDow<n>]:TRACe<t>:Y[:SCALe]:TOP on page 152
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6.1.2Configuring numerical results
Analysis
Configuring the display
Symbols
Turns symbols that represent a measurement point on the trace on and off.
Remote command:
DISPlay[:WINDow<n>]:TRACe<t>:SYMBols on page 149
X-Axis
Selects the frequency data that is displayed on the x-axis.
For measurements on frequency converting DUTs with a variable intermediate fre-
quency, you can display either the RF frequency or the IF frequency.
Note that a change of the x-axis scale applies to all result displays, and also deter-
mines which value is output for trace export.
The "Frequency Axis" scale is also available via the [FREQ] key.
Remote command:
DISPlay[:WINDow<n>]:TRACe<t>:X[:SCALe] on page 150
When configuring numerical results, the dialog box selects the type of results you want
to display in the result table. The results in the table are based on a particular trace
that you can select in the corresponding input field.
You can add an aspect of the measurement by placing a checkmark in front of the corresponding result on and remove it by removing the checkmark.
For more information on each result, see Chapter 3, "Measurements and result dis-
A trace is the graphical representation of a set of measurement results in a diagram.
Each measurement window that contains graphical results supports up to four individual traces. Each trace has a different color. Trace settings determine how the measured data is analyzed and displayed on the screen. The trace information, including a
color map and trace mode is summarized in the diagram header.
The "Trace 1 to 4" softkeys open the "Traces" tab of the "Trace Configuration" dialog
box.
The "Traces" tab contains functionality to configure a trace.
"Trace Selec-
tion"
"Trace Mode"
Remote command:
Trace mode:
DISPlay[:WINDow<n>]:TRACe<t>:MODE on page 153
The "Trace 1" to "Trace 4" buttons select a trace. If a trace is
selected, it is highlighted orange.
Note that you cannot select a trace if its trace mode is "Blank".
Selects the trace mode for the corresponding trace.
For more information, see Chapter 4, "Measurement basics",
on page 23.
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Analysis
Working with traces
Smoothing
If enabled, the trace is smoothed by the specified value (between 1 % and 50 %). The
smoothing value is defined as a percentage of the display width. The larger the
smoothing value, the greater the smoothing effect.
Restores the default configuration for all traces in a window.
Trace Export
The "Trace Export" tab contains functionality to export trace data.
Export all Traces and all Table Results ← Trace Export
Selects all displayed traces and result tables (e.g. Result Summary, marker table etc.)
in the current application for export to an ASCII file.
Alternatively, you can select one specific trace only for export (see Trace to Export).
The results are output in the same order as they are displayed on the screen: window
by window, trace by trace, and table row by table row.
Remote command:
FORMat:DEXPort:TRACes on page 156
Include Instrument & Measurement Settings ← Trace Export
Includes additional instrument and measurement settings in the header of the export
file for result data.
Remote command:
FORMat:DEXPort:HEADer on page 156
Trace to Export ← Trace Export
Defines an individual trace to be exported to a file.
This setting is not available if Export all Traces and all Table Results is selected.
Decimal Separator ← Trace Export
Defines the decimal separator for floating-point numerals for the data export/import
files. Evaluation programs require different separators in different languages.
Remote command:
FORMat:DEXPort:DSEParator on page 155
Export Trace to ASCII File ← Trace Export
Opens a file selection dialog box and saves the selected trace in ASCII format (.dat)
to the specified file and directory.
The results are output in the same order as they are displayed on the screen: window
by window, trace by trace, and table row by table row.
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Analysis
Using markers
The column headers are provided as the first row. Whether the frequency value represents the RF or IF frequency depends on the X-Axis setting.
Or: [TRACE] > "Copy Trace"
Copies trace data to another trace.
The first group of buttons (labeled "Trace 1" to "Trace 4") selects the source trace. The
second group of buttons (labeled "Copy to Trace 1" to "Copy to Trace 4") selects the
destination.
Remote command:
TRACe<n>:COPY on page 157
6.3Using markers
Markers help you to read out measurement results for particular frequencies or mark a
particular point on a trace. The "noise figure" application features four markers. Markers in the "noise figure" application are linked. If you use more than one measurement
window and activate a marker in one window, it also appears in all other measurement
windows on the same horizontal position.
Selects or turns the corresponding marker on and off.
Turning on a marker also opens an input field to define the horizontal position of the
marker.
By default, the first marker you turn on is a normal marker, all others are delta markers.
Marker Type
Toggles the marker type.
The type for marker 1 is always "Normal", the type for delta marker 1 is always "Delta".
These types cannot be changed.
Note: If normal marker 1 is the active marker, switching the "Mkr Type" activates an
additional delta marker 1. For any other marker, switching the marker type does not
activate an additional marker, it only switches the type of the selected marker.
"Normal"
"Delta"
Remote command:
CALCulate<n>:MARKer<m>[:STATe] on page 167
CALCulate<n>:DELTamarker<m>[:STATe] on page 169
A normal marker indicates the absolute value at the defined position
in the diagram.
A delta marker defines the value of the marker relative to the specified reference marker (marker 1 by default).
Marker to Trace
Opens an input field to assign the marker to a particular trace if you are using more
than one trace.
All Markers Off
Deactivates all markers in one step.
Remote command:
CALCulate<n>:MARKer<m>:AOFF on page 166
Marker Config
Opens the "Marker Configuration" dialog box.
The "Marker Configuration" dialog box contains all marker functions necessary to set
up the four markers supported by the application.
●
Selected
Highlights the currently selected marker.
●
State
Turns a marker on and off.
●
X-value
Defines the marker position on the horizontal axis.
●
Type
Selects the marker type. For more information see "Marker Type"on page 83.
●
Trace
Selects the trace the marker is positioned on.
Marker Table Display
Defines how the marker information is displayed.
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Analysis
Using markers
"On"
"Off"
Remote command:
DISPlay[:WINDow<n>]:MTABle on page 172
Marker Info
Turns the marker information displayed in the diagram on and off.
Remote command:
DISPlay[:WINDow<n>]:MINFo[:STATe] on page 172
Displays the marker information in a table in a separate area beneath
the diagram.
No separate marker table is displayed.
If Marker Info is active, the marker information is displayed within the
diagram area.
6.3.2Marker positioning
If you are using more than one measurement window, the application performs the
peak search in the currently selected measurement window. The currently selected
measurement window has a blue border. Because the markers are linked in the "noise
figure" application, the frequency position of the marker in the other window is updated
accordingly, even if it means that the marker is on a peak in one window only.
Search Next Minimum...................................................................................................85
Marker to Single Frequency..........................................................................................86
Select Marker <x>
Opens a dialog box to select and activate or deactivate one or more markers.
The number in the softkey label (<x>) shows the number of the currently selected
marker.
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Analysis
Using markers
Remote command:
Marker selected via suffix <m> in remote commands.
Peak Search
Sets the selected marker/delta marker to the maximum of the trace. If no marker is
active, marker 1 is activated.
Remote command:
CALCulate<n>:MARKer<m>:MAXimum[:PEAK] on page 173
CALCulate<n>:DELTamarker<m>:MAXimum[:PEAK] on page 175
Search Next Peak
Sets the selected marker/delta marker to the next (lower) maximum of the assigned
trace. If no marker is active, marker 1 is activated.
Remote command:
CALCulate<n>:MARKer<m>:MAXimum:NEXT on page 173
CALCulate<n>:MARKer<m>:MAXimum:RIGHt on page 173
CALCulate<n>:MARKer<m>:MAXimum:LEFT on page 173
CALCulate<n>:DELTamarker<m>:MAXimum:NEXT on page 175
CALCulate<n>:DELTamarker<m>:MAXimum:RIGHt on page 176
CALCulate<n>:DELTamarker<m>:MAXimum:LEFT on page 175
Search Minimum
Sets the selected marker/delta marker to the minimum of the trace. If no marker is
active, marker 1 is activated.
Remote command:
CALCulate<n>:MARKer<m>:MINimum[:PEAK] on page 174
CALCulate<n>:DELTamarker<m>:MINimum[:PEAK] on page 176
Search Next Minimum
Sets the selected marker/delta marker to the next (higher) minimum of the selected
trace. If no marker is active, marker 1 is activated.
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Analysis
Using markers
Remote command:
CALCulate<n>:MARKer<m>:MINimum:NEXT on page 174
CALCulate<n>:MARKer<m>:MINimum:LEFT on page 174
CALCulate<n>:MARKer<m>:MINimum:RIGHt on page 174
CALCulate<n>:DELTamarker<m>:MINimum:NEXT on page 176
CALCulate<n>:DELTamarker<m>:MINimum:LEFT on page 176
CALCulate<n>:DELTamarker<m>:MINimum:RIGHt on page 176
Marker to Single Frequency
Starts a single frequency measurement on the current marker position.
When you use this function, the application changes the tuning mode and automati-
cally adjusts the single frequency to that of the current marker position.
For more information see Chapter 4.1.3, "Single frequency measurements",
on page 25.
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7Remote control commands for noise figure
Remote control commands for noise figure measurements
measurements
The following remote control commands are required to configure and perform "noise
figure" measurements in a remote environment. The R&S FPL1000 must already be
set up for remote operation in a network as described in the base unit manual.
Common functionality
Note that basic tasks that are also performed in the base unit in the same way are not
described here. For a description of such tasks, see the R&S FPL1000 User Manual.
In particular, this includes:
●
Managing Settings and Results, i.e. storing and loading settings and result data.
●
Basic instrument configuration, e.g. checking the system configuration, customizing
the screen layout, or configuring networks and remote operation.
●
Using the common status registers (specific status registers for Pulse measurements are not used).
Channel Setup-specific commands
Apart from a few general commands on the R&S FPL1000, most commands refer to
the currently active channel setup. Thus, always remember to activate a "Noise Figure"
channel setup before starting a remote program for a "noise figure" measurement.
●Configuring the display..........................................................................................149
●Working with traces...............................................................................................152
●Working with limit lines..........................................................................................157
●Working with markers............................................................................................166
●Using the status register....................................................................................... 177
●Deprecated remote commands for noise figure measurements........................... 183
●Programming example: measuring a noise figure.................................................184
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7.1Common suffixes
Remote control commands for noise figure measurements
Introduction
In the R&S FPL1 Noise Figure measurements application, the following common suffixes are used in remote commands:
Table 7-1: Common suffixes used in remote commands in the R&S FPL1 Noise Figure measurements
SuffixValue rangeDescription
<m>1 to 4Marker
<n>1 to 16Window (in the currently selected channel setup)
<t>1 to 4Trace
<li>1 to 8Limit line
application
7.2Introduction
Commands are program messages that a controller (e.g. a PC) sends to the instrument or software. They operate its functions ('setting commands' or 'events') and
request information ('query commands'). Some commands can only be used in one
way, others work in two ways (setting and query). If not indicated otherwise, the commands can be used for settings and queries.
The syntax of a SCPI command consists of a header and, usually, one or more parameters. To use a command as a query, you have to append a question mark after the
last header element, even if the command contains a parameter.
A header contains one or more keywords, separated by a colon. Header and parameters are separated by a "white space" (ASCII code 0 to 9, 11 to 32 decimal, e.g. blank).
If there is more than one parameter for a command, they are separated by a comma
from one another.
Only the most important characteristics that you need to know when working with SCPI
commands are described here. For a more complete description, refer to the user
manual of the R&S FPL1000.
Remote command examples
Note that some remote command examples mentioned in this general introduction are
possibly not supported by this particular application.
7.2.1Conventions used in descriptions
The following conventions are used in the remote command descriptions:
●
Command usage
If not specified otherwise, commands can be used both for setting and for querying
parameters.
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Remote control commands for noise figure measurements
Introduction
If a command can be used for setting or querying only, or if it initiates an event, the
usage is stated explicitly.
●
Parameter usage
If not specified otherwise, a parameter can be used to set a value and it is the
result of a query.
Parameters required only for setting are indicated as Setting parameters.
Parameters required only to refine a query are indicated as Query parameters.
Parameters that are only returned as the result of a query are indicated as Returnvalues.
●
Conformity
Commands that are taken from the SCPI standard are indicated as SCPI confirmed. All commands used by the R&S FPL1000 follow the SCPI syntax rules.
●
Asynchronous commands
A command which does not automatically finish executing before the next command starts executing (overlapping command) is indicated as an Asynchronouscommand.
●
Reset values (*RST)
Default parameter values that are used directly after resetting the instrument (*RST
command) are indicated as *RST values, if available.
●
Default unit
The default unit is used for numeric values if no other unit is provided with the
parameter.
●
Manual operation
If the result of a remote command can also be achieved in manual operation, a link
to the description is inserted.
7.2.2Long and short form
The keywords have a long and a short form. You can use either the long or the short
form, but no other abbreviations of the keywords.
The short form is emphasized in uppercase letters. Note however, that this emphasis
only serves the purpose to distinguish the short from the long form in the manual. For
the instrument, the case does not matter.
Example:
SENSe:FREQuency:CENTer is the same as SENS:FREQ:CENT.
7.2.3Numeric suffixes
Some keywords have a numeric suffix if the command can be applied to multiple
instances of an object. In that case, the suffix selects a particular instance (e.g. a measurement window).
Numeric suffixes are indicated by angular brackets (<n>) next to the keyword.
If you do not quote a suffix for keywords that support one, a 1 is assumed.
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7.2.4Optional keywords
Remote control commands for noise figure measurements
Introduction
Example:
DISPlay[:WINDow<1...4>]:ZOOM:STATe enables the zoom in a particular measurement window, selected by the suffix at WINDow.
DISPlay:WINDow4:ZOOM:STATe ON refers to window 4.
Some keywords are optional and are only part of the syntax because of SCPI compliance. You can include them in the header or not.
If an optional keyword has a numeric suffix and you need to use the suffix, you have to
include the optional keyword. Otherwise, the suffix of the missing keyword is assumed
to be the value 1.
Optional keywords are emphasized with square brackets.
Example:
Without a numeric suffix in the optional keyword:
[SENSe:]FREQuency:CENTer is the same as FREQuency:CENTer
With a numeric suffix in the optional keyword:
DISPlay[:WINDow<1...4>]:ZOOM:STATe
DISPlay:ZOOM:STATe ON enables the zoom in window 1 (no suffix).
DISPlay:WINDow4:ZOOM:STATe ON enables the zoom in window 4.
7.2.5Alternative keywords
A vertical stroke indicates alternatives for a specific keyword. You can use both keywords to the same effect.
Example:
[SENSe:]BANDwidth|BWIDth[:RESolution]
In the short form without optional keywords, BAND 1MHZ would have the same effect
as BWID 1MHZ.
7.2.6SCPI parameters
Many commands feature one or more parameters.
If a command supports more than one parameter, they are separated by a comma.
Example:
LAYout:ADD:WINDow Spectrum,LEFT,MTABle
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7.2.6.1Numeric values
Remote control commands for noise figure measurements
Numeric values can be entered in any form, i.e. with sign, decimal point or exponent.
For physical quantities, you can also add the unit. If the unit is missing, the command
uses the basic unit.
Example:
With unit: SENSe:FREQuency:CENTer 1GHZ
Without unit: SENSe:FREQuency:CENTer 1E9 would also set a frequency of 1 GHz.
Values exceeding the resolution of the instrument are rounded up or down.
If the number you have entered is not supported (e.g. for discrete steps), the command
returns an error.
Instead of a number, you can also set numeric values with a text parameter in special
cases.
●
MIN/MAX
Defines the minimum or maximum numeric value that is supported.
●
DEF
Defines the default value.
●
UP/DOWN
Increases or decreases the numeric value by one step. The step size depends on
the setting. Sometimes, you can customize the step size with a corresponding
command.
Querying numeric values
When you query numeric values, the system returns a number. For physical quantities,
it applies the basic unit (e.g. Hz for frequencies). The number of digits after the decimal
point depends on the type of numeric value.
Example:
Setting: SENSe:FREQuency:CENTer 1GHZ
Query: SENSe:FREQuency:CENTer? would return 1E9
Sometimes, numeric values are returned as text.
●
INF/NINF
Infinity or negative infinity. Represents the numeric values 9.9E37 or -9.9E37.
●
NAN
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7.2.6.2Boolean
Remote control commands for noise figure measurements
Introduction
Not a number. Represents the numeric value 9.91E37. NAN is returned if errors
occur.
Boolean parameters represent two states. The "on" state (logically true) is represented
by "ON" or the numeric value 1. The "off" state (logically untrue) is represented by
"OFF" or the numeric value 0.
Querying Boolean parameters
When you query Boolean parameters, the system returns either the value 1 ("ON") or
the value 0 ("OFF").
Example:
Setting: DISPlay:WINDow:ZOOM:STATe ON
Query: DISPlay:WINDow:ZOOM:STATe? would return 1
7.2.6.3Character data
Character data follows the syntactic rules of keywords. You can enter text using a short
or a long form. For more information, see Chapter 7.2.2, "Long and short form",
on page 89.
Querying text parameters
When you query text parameters, the system returns its short form.
Example:
Setting: SENSe:BANDwidth:RESolution:TYPE NORMal
Query: SENSe:BANDwidth:RESolution:TYPE? would return NORM
7.2.6.4Character strings
Strings are alphanumeric characters. They have to be in straight quotation marks. You
can use a single quotation mark ( ' ) or a double quotation mark ( " ).
Example:
INSTRument:DELete 'Spectrum'
7.2.6.5Block data
Block data is a format which is suitable for the transmission of large amounts of data.
The ASCII character # introduces the data block. The next number indicates how many
of the following digits describe the length of the data block. The data bytes follow. During the transmission of these data bytes, all end or other control signs are ignored until
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7.3Controlling the noise figure measurement channel
Remote control commands for noise figure measurements
Controlling the noise figure measurement channel
all bytes are transmitted. #0 specifies a data block of indefinite length. The use of the
indefinite format requires an NL^END message to terminate the data block. This format
is useful when the length of the transmission is not known or if speed or other considerations prevent segmentation of the data into blocks of definite length.
The following commands are necessary to control the measurement channel.
This command duplicates the currently selected channel setup, i.e creates a new channel setup of the same type and with the identical measurement settings. The name of
the new channel setup is the same as the copied channel setup, extended by a consecutive number (e.g. "IQAnalyzer" -> "IQAnalyzer 2").
The channel setup to be duplicated must be selected first using the INST:SEL command.
Example:
INST:SEL 'IQAnalyzer'
INST:CRE:DUPL
Duplicates the channel setup named 'IQAnalyzer' and creates a
new channel setup named 'IQAnalyzer2'.
This command replaces a channel setup with another one.
Setting parameters:
<ChannelName1>String containing the name of the channel setup you want to
replace.
<ChannelType>Channel type of the new channel setup.
For a list of available channel setup types see INSTrument:
LIST? on page 94.
<ChannelName2>String containing the name of the new channel setup.
Note: If the specified name for a new channel setup already
exists, the default name, extended by a sequential number, is
used for the new channel setup (see INSTrument:LIST?
on page 94).
Channel names can have a maximum of 31 characters, and
must be compatible with the Windows conventions for file
names. In particular, they must not contain special characters
such as ":", "*", "?".
Example:
Usage: Setting only
INSTrument:DELete <ChannelName>
This command deletes a channel setup.
Setting parameters:
<ChannelName>String containing the name of the channel setup you want to
Usage: Setting only
INSTrument:LIST?
This command queries all active channel setups. This is useful in order to obtain the
names of the existing channel setups, which are required in order to replace or delete
the channel setups.
Return values:
<ChannelType>,
<ChannelName>
INST:CRE:REPL 'IQAnalyzer2',IQ,'IQAnalyzer'
Replaces the channel setup named "IQAnalyzer2" by a new
channel setup of type "IQ Analyzer" named "IQAnalyzer".
delete.
A channel setup must exist in order to be able delete it.
For each channel setup, the command returns the channel setup
type and channel setup name (see tables below).
Tip: to change the channel setup name, use the INSTrument:
REName command.
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Remote control commands for noise figure measurements
Note: the default channel setup name is also listed in the table. If the specified name for a new channel
setup already exists, the default name, extended by a sequential number, is used for the new channel
setup.
ADEMAnalog Demod
NOISENoise
DDEMVSA
INSTrument:REName <ChannelName1>, <ChannelName2>
This command renames a channel setup.
Setting parameters:
<ChannelName1>String containing the name of the channel setup you want to
rename.
<ChannelName2>String containing the new channel setup name.
Note that you cannot assign an existing channel setup name to
a new channel setup; this will cause an error.
Channel names can have a maximum of 31 characters, and
must be compatible with the Windows conventions for file
names. In particular, they must not contain special characters
such as ":", "*", "?".
Example:
INST:REN 'IQAnalyzer2','IQAnalyzer3'
Renames the channel setup with the name 'IQAnalyzer2' to
'IQAnalyzer3'.
Usage: Setting only
INSTrument[:SELect] <ChannelType> | <ChannelName>
This command activates a new channel setup with the defined channel setup type, or
selects an existing channel setup with the specified name.
Also see
●
INSTrument:CREate[:NEW] on page 93
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Remote control commands for noise figure measurements
Working with windows in the display
Parameters:
<ChannelType>Channel type of the new channel setup.
For a list of available channel setup types see INSTrument:
LIST? on page 94.
<ChannelName>String containing the name of the channel setup.
Example:
INST IQ
INST 'MyIQSpectrum'
Selects the channel setup named 'MyIQSpectrum' (for example
before executing further commands for that channel setup).
SYSTem:PRESet:CHANnel[:EXEC]
This command restores the default instrument settings in the current channel setup.
Use INST:SEL to select the channel setup.
Example:
INST:SEL 'Spectrum2'
Selects the channel setup for "Spectrum2".
SYST:PRES:CHAN:EXEC
Restores the factory default settings to the "Spectrum2" channel
setup.
Usage: Event
Manual operation: See "Preset Channel Setup"on page 41
7.4Working with windows in the display
The following commands are required to change the evaluation type and rearrange the
screen layout for a channel setup as you do using the SmartGrid in manual operation.
Since the available evaluation types depend on the selected application, some parameters for the following commands also depend on the selected channel setup.
Note that the suffix <n> always refers to the window in the currently selected channelsetup.
This command adds a window to the display in the active channel setup.
This command is always used as a query so that you immediately obtain the name of
the new window as a result.
To replace an existing window, use the LAYout:REPLace[:WINDow] command.
Query parameters:
<WindowName>String containing the name of the existing window the new win-
dow is inserted next to.
By default, the name of a window is the same as its index. To
determine the name and index of all active windows, use the
LAYout:CATalog[:WINDow]? query.
<Direction>LEFT | RIGHt | ABOVe | BELow
Direction the new window is added relative to the existing window.
<WindowType>text value
Type of result display (evaluation method) you want to add.
See the table below for available parameter values.
Return values:
<NewWindowName> When adding a new window, the command returns its name (by
default the same as its number) as a result.
Example:
LAY:ADD? '1',LEFT,MTAB
Result:
'2'
Adds a new window named '2' with a marker table to the left of
window 1.
Usage: Query only
Manual operation: See "Noise Figure"on page 15
See "Gain"on page 16
See "Noise Temperature"on page 16
See "Y-Factor"on page 17
See "ENR Measured"on page 18
See "Power (Hot)"on page 19
See "Power (Cold)"on page 19
See "Cal Y-Factor"on page 20
See "Cal Power (Hot)"on page 20
See "Cal Power (Cold)"on page 21
See "Result Table"on page 21
See "Marker Table"on page 22
Table 7-3: <WindowType> parameter values for Noise Figure application
Parameter valueWindow type
CPColdCal Power (Cold)
CPHotCal Power (Hot)
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Remote control commands for noise figure measurements
Working with windows in the display
Parameter valueWindow type
CYFactor"Cal Y-Factor"
ENRENR Measured
"GAIN""Gain" result display
MTABleMarker table
NOISe"Noise figure" result display
PCOLdPower cold result display
PHOTPower hot result display
RESultsResult table
TEMPerature"Noise temperature" result display
YFACtor"Y-Factor" result display
LAYout:CATalog[:WINDow]?
This command queries the name and index of all active windows in the active channel
setup from top left to bottom right. The result is a comma-separated list of values for
each window, with the syntax:
Name of the window.
In the default state, the name of the window is its index.
<WindowIndex>numeric value
Index of the window.
Example:
LAY:CAT?
Result:
'2',2,'1',1
Two windows are displayed, named '2' (at the top or left), and '1'
(at the bottom or right).
Usage: Query only
LAYout:IDENtify[:WINDow]? <WindowName>
This command queries the index of a particular display window in the active channel
setup.
Note: to query the name of a particular window, use the LAYout:WINDow<n>:
IDENtify? query.
Query parameters:
<WindowName>String containing the name of a window.
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Working with windows in the display
Return values:
<WindowIndex>Index number of the window.
Example:
Usage: Query only
LAYout:REMove[:WINDow] <WindowName>
This command removes a window from the display in the active channel.
Setting parameters:
<WindowName>String containing the name of the window. In the default state,
Example:
Usage: Setting only
LAYout:REPLace[:WINDow] <WindowName>,<WindowType>
This command replaces the window type (for example from "Diagram" to "Result Summary") of an already existing window in the active channel setup while keeping its position, index and window name.
LAY:WIND:IDEN? '2'
Queries the index of the result display named '2'.
Response:
2
the name of the window is its index.
LAY:REM '2'
Removes the result display in the window named '2'.
To add a new window, use the LAYout:ADD[:WINDow]? command.
Setting parameters:
<WindowName>String containing the name of the existing window.
By default, the name of a window is the same as its index. To
determine the name and index of all active windows in the active
channel setup, use the LAYout:CATalog[:WINDow]? query.
<WindowType>Type of result display you want to use in the existing window.
See LAYout:ADD[:WINDow]?on page 97 for a list of available
window types.
Example:
Usage: Setting only
LAYout:SPLitter <Index1>, <Index2>, <Position>
This command changes the position of a splitter and thus controls the size of the windows on each side of the splitter.
Note that windows must have a certain minimum size. If the position you define conflicts with the minimum size of any of the affected windows, the command will not work,
but does not return an error.
LAY:REPL:WIND '1',MTAB
Replaces the result display in window 1 with a marker table.
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Remote control commands for noise figure measurements
Working with windows in the display
Figure 7-1: SmartGrid coordinates for remote control of the splitters
Setting parameters:
<Index1>The index of one window the splitter controls.
<Index2>The index of a window on the other side of the splitter.
<Position>New vertical or horizontal position of the splitter as a fraction of
the screen area (without channel and status bar and softkey
menu).
The point of origin (x = 0, y = 0) is in the lower left corner of the
screen. The end point (x = 100, y = 100) is in the upper right corner of the screen. (See Figure 7-1.)
The direction in which the splitter is moved depends on the
screen layout. If the windows are positioned horizontally, the
splitter also moves horizontally. If the windows are positioned
vertically, the splitter also moves vertically.
Range: 0 to 100
Example:
LAY:SPL 1,3,50
Moves the splitter between window 1 ('Frequency Sweep') and 3
('Marker Table') to the center (50%) of the screen, i.e. in the figure above, to the left.
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