Agilent 8702E
Lightwave Component Analyzer
User’s Guide
© Copyright
Agilent Technologies 2001
All Rights Reserved. Reproduction, adaptation, or translation without prior written
permission is prohibited,
except as allowed under copyright laws.
Agilent Part No. 08702-91028
Printed in USA
March 2001
Agilent Technologies
Lightwave Division
3910 Brickway BoulevardSanta Rosa, CA 95403, USA
Notice.
The information contained in
this document is subject to
change without notice. Companies, names, and data used
in examples herein are fictitious unless otherwise noted.
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no warranty of any kind with
regard to this material, including but not limited to, the
implied warranties of merchantability and fitness for a
particular purpose. Agilent
Technologies shall not be liable for errors contained herein
or for incidental or consequential damages in connection with the furnishing,
performance, or use of this
material.
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forth in subparagraph (c) (1)
(ii) of the Rights in Technical
Data and Computer Software
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for DOD agencies, and subparagraphs (c) (1) and (c) (2)
of the Commercial Computer
Software Restricted Rights
clause at FAR 52.227-19 for
other agencies.
Warranty.
This Agilent Technologies
instrument product is warranted against defects in
material and workmanship for
a period of one year from date
of shipment. During the warranty period, Agilent Technologies will, at its option, either
repair or replace products
which prove to be defective.
For warranty service or repair,
this product must be returned
to a service facility designated by Agilent Technologies. Buyer shall prepay
shipping charges to Agilent
Technologies and Agilent
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product to Buyer. However,
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charges, duties, and taxes for
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Agilent Technologies warrants that its software and
firmware designated by Agilent Technologies for use with
an instrument will execute its
programming instructions
when properly installed on
that instrument. Agilent Technologies does not warrant that
the operation of the instrument, or software, or firmware
will be uninterrupted or errorfree.
Limitation of Warranty.
The foregoing warranty shall
not apply to defects resulting
from improper or inadequate
maintenance by Buyer, Buyersupplied software or interfacing, unauthorized modification or misuse, operation
outside of the environmental
specifications for the product,
or improper site preparation
or maintenance.
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expressed or implied. Agilent
Technologies specifically disclaims the implied warranties
of merchantability and fitness
for a particular purpose.
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The remedies provided herein
are buyer's sole and exclusive
remedies. Agilent Technologies shall not be liable for any
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legal theory.
Safety Symbols.
CAUTION
The
caution
sign denotes a
hazard. It calls attention to a
procedure which, if not correctly performed or adhered
to, could result in damage to
or destruction of the product.
Do not proceed beyond a caution sign until the indicated
conditions are fully understood and met.
WAR NI NG
The
warning
sign denotes a
hazard. It calls attention to a
procedure which, if not correctly performed or adhered
to, could result in injury or
loss of life. Do not proceed
beyond a warning sign until
the indicated conditions are
fully understood and met.
The instruction manual symbol. The product is marked with this
warning symbol when
it is necessary for the
user to refer to the
instructions in the
manual.
The laser radiation
symbol. This warning
symbol is marked on
products which have a
laser output.
The AC symbol is used
to indicate the
required nature of the
line module input
power.
The ON symbols are
|
used to mark the positions of the instrument
power line switch.
The OFF symbols
❍
are used to mark the
positions of the instrument power line
switch.
The CE mark is a registered trademark of
the European Community.
The CSA mark is a registered trademark of
the Canadian Standards Association.
The C-Tick mark is a
registered trademark
of the Australian Spectrum Management
Agency.
This text denotes the
ISM1-A
instrument is an
Industrial Scientific
and Medical Group 1
Class A product.
Typographical Conventions.
The following conventions are
used in this book:
Key type
for keys or text
located on the keyboard or
instrument.
Softkey type
for key names that
are displayed on the instrument’s screen.
Display type
for words or
characters displayed on the
computer’s screen or instrument’s display.
User type
for words or charac-
ters that you type or enter.
Emphasis
type for words or
characters that emphasize
some point or that are used as
place holders for text that you
type.
ii
The Agilent 8702E—At a Glance
The Agilent 8702E—At a Glance
The Agilent 8702E performs optical and electrical transmission and reflection
measurements on lightwave systems and components. For most measurements, the Agilent 8702E imposes an electrical modulation signal on a lightwave carrier and then measures the device’s response to the
lightwave signal. Typically, the Agilent 8702E is used with the Agilent 83400series lightwave sources and receivers.
You can perform the following transmission measurements:
• Gain and loss of an optical amplifier
• Responsivity of a photo detector
• Fault location on a fiber-optic cable
•Group delay
• Insertion phase shift
The following reflection measurements are also possible:
• Return loss of modulated laser source
• Standing wave ratio (SWR)
• Impedance (R + jX)
modulated
Measurement accuracy—it’s up to you!
Electrical and fiber-optic connectors are easily damaged when connected to dirty or
damaged cables and accessories. The Agilent 8702E’s front-panel PORT 1 and PORT 2
connector is no exception. When you use improper cleaning and handling techniques,
you risk expensive instrument repairs, damaged cables, and compromised measurements. Before you connect any cables, refer to “Cleaning Connections for Accurate Mea-
surements” on page 1-32.
The electrical connectors are also sensitive to electrostatic discharge. Before you connect any cable to the Agilent 8702E, refer to “Protecting Against Electrostatic Damage”
on page 1-30.
iii
The Agilent 8702E—At a Glance
Several types of devices can be characterized
With the Agilent 8702E, you can characterize four types of devices which are
categorized according to their input and output ports. They are optical
devices, lightwave sources, lightwave receivers, and electrical devices. Optical
devices include fiber-optic cables, and couplers.
The Agilent 8702E can make electrical measurements because it has all the
capabilities of an RF/microwave network analyzer. During electrical measurements, a device’s response to an RF signal is measured.
Measurements are displayed in several formats
Depending on the measurement performed, the data can be viewed using one
of several display formats:
• Logarithmic or linear magnitude
• Smith chart
•Polar
• Standing wave ratio
•Phase
• Real or imaginary
Time-domain measurements
In addition to transmission and reflection measurements, the Agilent 8702E
can locate faults on fiber-optic cables and other devices. It locates faults or
discontinuities in time or distance.
CAUTION
Displayed results can be saved and printed
You can get hardcopy results of your measurements by connecting a printer to
the rear-panel
PARALLEL PRINTER PORT
connector. In addition, measurement
results, instrument settings, and calibrations can be saved on a DOS-formatted
disk using the front-panel disk drive.
The Agilent 8702E’s
PORT 1
and
PORT 2
connectors are static sensitive. Do not
touch the center conductor of these connectors. Do not allow any static charge
to come into contact with it.
iv
General Safety Considerations
General Safety Considerations
This product has been designed and tested in accordance with IEC Publication 61010-1, Safety Requirements for Electrical Equipment for Measurement,
Control and Laboratory Use, and has been supplied in a safe condition. The
instruction documentation contains information and warnings that must be
followed by the user to ensure safe operation and to maintain the product in a
safe condition.
WARNING
WARNING
WARNING
WARNING
WARNING
If this instrument is not used as specified, the protection provided by
the equipment could be impaired. This instrument must be used in a
normal condition (in which all means for protection are intact) only.
To prevent electrical shock, disconnect the Agilent 8702E from mains
before cleaning. Use a dry cloth or one slightly dampened with water
to clean the external case parts. Do not attempt to clean internally.
This is a Safety Class 1 product (provided with a protective earthing
ground incorporated in the power cord). The mains plug shall only be
inserted in a socket outlet provided with a protective earth contact.
Any interruption of the protective conductor inside or outside of the
product is likely to make the product dangerous. Intentional
interruption is prohibited.
No operator serviceable parts inside. Refer servicing to qualified
personnel. To prevent electrical shock, do not remove covers.
For continued protection against fire hazard, replace line fuse only
with same type and ratings, (type T 0.315A/250V for 100/120V
operation and 0.16A/250V for 220/240V operation). The use of other
fuses or materials is prohibited. Verify that the value of the linevoltage fuse is correct.
• For 100/120V operation, use an IEC 127 5×20 mm, 0.315 A, 250 V, Agilent
part number 2110-0449.
• For 220/240V operation, use an IEC 127 5×20 mm, 0.16 A, 250 V, Agilent
Technologies part number 2110-0448.
v
General Safety Considerations
CAUTION
CAUTION
CAUTION
CAUTION
CAUTION
CAUTION
Before switching on this instrument, make sure that the line voltage selector
switch is set to the line voltage of the power supply and the correct fuse is
installed. Assure the supply voltage is in the specified range.
This product is designed for use in INSTALLATION CATEGORY II and
POLLUTION DEGREE 2, per IEC 1010 and 664 respectively.
VENTILATION REQUIREMENTS: When installing the product in a cabinet, the
convection into and out of the product must not be restricted. The ambient
temperature (outside the cabinet) must be less than the maximum operating
temperature of the product by 4°C for every 100 watts dissipated in the
cabinet. If the total power dissipated in the cabinet is greater than 800 watts,
then forced convection must be used.
Always use the three-prong ac power cord supplied with this instrument.
Failure to ensure adequate earth grounding by not using this cord may cause
instrument damage.
connect ac power until you have verified the line voltage is correct.
Do not
Damage to the equipment could result.
This instrument has autoranging line voltage input. Be sure the supply voltage
is within the specified range.
vi
Contents
The Agilent 8702E—At a Glance iii
General Safety Considerations v
1 Getting Started
A Quick Tour 1-3
Changing Instrument Settings 1-11
Making Measurements Using Guided Setup 1-14
Setting the RF Output 1-20
Protecting Against Electrostatic Damage 1-30
Cleaning Connections for Accurate Measurements 1-32
2 Measuring Lightwave Sources
Making Transmission Measurements 2-3
Making Reflection Measurements 2-7
3 Measuring Lightwave Receivers
Making Transmission Measurements 3-4
Making Reflection Measurements 3-8
Measuring Phase Distortion 3-11
4 Measuring Electrical Devices
Measuring Magnitude and Insertion Phase Response 4-3
Measuring Electrical Length and Phase Distortion 4-7
Performing Time Domain Measurements 4-19
Reducing Receiver Crosstalk 4-27
Amplifier Testing 4-28
Performing Swept Power Measurements 4-32
Measuring Gain Compression 4-33
Measuring Gain and Reverse Isolation Simultaneously 4-37
Performing Harmonic Measurements (Option 002) 4-39
Mixer Testing 4-43
Performing On-Wafer Measurements 4-59
Connection Considerations 4-60
5 Measuring Optical Devices
Making Transmission Measurements 5-3
Making Reflection Measurements 5-8
Contents-1
Contents
Making Time Domain Measurements 5-13
6 Optimizing Measurements
Display Functions 6-3
Increasing Measurement Accuracy 6-8
Changing the Display Format 6-11
Displaying and Saving Traces 6-18
Increasing Sweep Speed 6-22
Increasing Dynamic Range 6-26
Reducing Trace Noise 6-28
Reducing Receiver Crosstalk 6-32
Knowing the Instrument Modes 6-33
7 Measuring with Markers
General Information 7-3
Activating Markers 7-8
Setting the Measurement Range 7-11
Making Relative Measurements 7-17
Searching with Markers 7-20
Making Statistical Measurements 7-23
Using Markers with Other Display Formats 7-25
Making Other Measurements 7-28
8 Making Mixer Measurements
Measurement Considerations 8-2
Conversion Loss Using the Frequency Offset Mode 8-3
High Dynamic Range Swept RF/IF Conversion Loss 8-9
Conversion Loss Using the Tuned Receiver Mode 8-12
Phase or Group Delay Measurements 8-17
Conversion Compression Using the Frequency Offset Mode 8-20
Isolation Example Measurements 8-25
Power Meter Calibration for Mixer Measurements 8-30
9 Saving Data, States, and the Display
Saving Instrument States 9-3
Saving Measurement Data 9-6
Saving the Display to a File 9-9
Contents-2
Formatting Disks 9-10
If You Have Problems with Disk Storage 9-11
10 Using Limit Lines
General Information 10-3
Example 1. Creating Flat Limits 10-9
Example 2. Creating Sloping Limits 10-12
Example 3. Creating Single-Point Limits 10-14
11 Creating Sequences
General Information 11-3
Creating and Editing Sequences 11-10
Running Sequences 11-18
Saving and Printing 11-19
12 Printing and Plotting
Saving the Display to a File 12-3
Printing or Plotting the Display 12-4
Displaying Lists 12-6
Selecting Options 12-7
Connecting Printers, Plotters, and Disk Drives 12-15
If You Encounter Problems with Printing or Plotting 12-19
Contents
13 Performing Calibrations
Entering Calibration Kits and Standards 13-3
Modifying User-Defined Electrical Kits 13-6
Performing Error-Correction 13-11
Procedures for Error-Correcting Measurements 13-18
Modifying Optical Standards 13-48
Calibrating with a Power Meter 13-50
Contents-3
Contents
Contents-4
1
A Quick Tour 1-3
Front panel 1-3
Display 1-6
Rear panel 1-8
Changing Instrument Settings 1-11
Making Measurements Using Guided Setup 1-14
To make an O/E measurement 1-15
Setting the RF Output 1-20
Defining the frequency range 1-20
Understanding the power ranges 1-21
Power coupling options 1-22
Source attenuator switch protection 1-23
Sweep time 1-23
Sweep types 1-26
Alternate and chop sweep modes 1-28
Protecting Against Electrostatic Damage 1-30
Cleaning Connections for Accurate Measurements 1-32
Getting Started
Getting Started
Getting Started
Getting Started
This chapter will introduce you to the Agilent 8702E’s basic features and controls. It also shows how to make transmission and reflection measurements
using
guided setups
through a measurement. Guided setups provide a fast and easy method of performing lightwave measurements. After you become proficient at making simple measurements, read Chapter 2, “Measuring Lightwave Sources” through
Chapter 5, “Measuring Optical Devices”.
Read “Setting the RF Output” on page 1-20, to learn how to set the RF start
frequency, stop frequency, and power level for your measurements. Although
you can configure these settings from within guided setups, understanding
how to control them manually will help you to get the most from your measurements.
Be sure to read the last two sections of this chapter. They show you how to
protect your instrument from damage.
. Guided setups are a series of menus which step you
CAUTION
The Agilent 8702E’s
touch the center conductor of these connectors. Do not allow any static charge
to come into contact with them. To protect your instrument, study the
information located in “Protecting Against Electrostatic Damage” on page 1-30.
1-2
PORT 1
and
PORT 2
connectors are static sensitive. Do not
Getting Started
A Quick Tour
A Quick Tour
Use this section to identify the instrument’s front and rear panel features and
to learn how to change the instrument’s settings.
Front panel
Figure 1-1. Agilent 8702E Front Panel
1
LINE switch. This switch controls ac power to the analyzer. 1 is on, 0 is off.
2
Display. This shows the measurement data traces, measurement annotation,
and softkey labels. The display is divided into specific information areas,
1-3
Getting Started
A Quick Tour
illustrated in Figure 1-2.
3
Softkeys. These keys provide access to menus that are shown on the display.
4
STIMULUS function block. The keys in this block allow you to control the
analyzer source’s frequency, power, and other stimulus functions.
5
RESPONSE function block. The keys in this block allow you to control the
measurement and display functions of the active display channel.
6
ACTIVE CHANNEL keys. The analyzer has two independent display channels.
These keys allow you to select the active channel. Then any function you enter
applies to this active channel.
7
The ENTRY block. This block includes the knob, the step (⇑, ⇓) keys, and the
1
number pad. These allow you to enter numerical data and control the markers.
8
INSTRUMENT STATE function block. These keys allow you to control
channel-independent system functions, such as the following:
• copying, save/recall, and GPIB controller mode
• limit testing
• external source mode
• tuned receiver mode
• frequency offset mode
• test sequence function
• harmonic measurements (Option 002)
• time domain transform
GPIB STATUS indicators are also included in this block.
PRESET
9
key. This key returns the instrument to either a known factory preset
state, or a user preset state that can be defined.
10
PORT 1 and PORT 2. These ports output a signal from the source and receive
input signals from a device under test. PORT 1 allows you to measure S
S
. PORT 2 allows you to measure S21 and S22.
11
Option 011 R, A, and B connector. These connectors allow you to apply input
signals when creating your own test setup. In addition these connectors allow
you to use the Agilent 85046A/B, 85047A, or 85044A/B test sets to simplify
measurement setup.
Option 011 RF OUT connector. This connects the RF output signal from the
analyzer’s internal source to a test set or power splitter.
11
PROBE POWER connector. This connector (fused inside the instrument)
1. Channels three and four are not supported.
1-4
and
12
Getting Started
A Quick Tour
supplies power to an active probe for in-circuit measurements of ac circuits.
12
R CHANNEL connectors. These connectors allow you to apply an input signal
to the analyzer’s R channel, for frequency offset mode.
13
Disk drive. This 3.5-inch drive allows you to store and recall instrument states
and measurement results for later analysis.
1-5
Getting Started
A Quick Tour
Display
Figure 1-2. Analyzer Display (Single Channel, Cartesian Format)
The analyzer display shows various measurement information:
• the grid where the analyzer plots the measurement data.
• the currently selected measurement parameters.
• the measurement data traces.
1
Stimulus Start Value. This value could be any one of the following:
• the start frequency of the source in frequency domain measurements.
• the start time in CW mode (0 seconds) or time domain measurements.
• the lower power value in power sweep.
When the stimulus is in center/span mode, the center stimulus value is shown
in this space.
2
Stimulus Stop Value. This value could be any one of the following:
• the stop frequency of the source in frequency domain measurements.
• the stop time in time domain measurements or CW sweeps.
• the upper limit of a power sweep.
1-6
Getting Started
A Quick Tour
When the stimulus is in center/span mode, the span is shown in this space. The
stimulus values can be blanked.
3
Status Notations. This area shows the current status of various functions for
the active channel.
4
Active Entry Area. This displays the active function and its current value.
5
Message Area. This displays prompts or error messages.
6
Title. This is a descriptive alpha-numeric string title that you define and enter
through an attached keyboard.
7
Active Channel. This is the number of the current active channel, selected with
ACTIVE CHANNEL
the
keys. If dual channel is on with an overlaid display, both
channel 1 and channel 2 appear in this area.
8
Measured Input(s). This shows the S-parameter, input, or ratio of inputs
currently measured, as selected using the
MEAS
key. Also indicated in this area
is the current display memory status.
9
Format. This is the display format that you selected using the
10
Scale/Div. This is the scale that you selected using the
SCALE REF
FORMAT
key, in units
appropriate to the current measurement.
11
Reference Level. This value is the reference line in Cartesian formats or the
outer circle in polar formats, whichever you selected using the
SCALE REF
The reference level is also indicated by a small triangle adjacent to the
graticule, at the left for channel 1 and at the right for channel 2.
12
Marker Values. These are the values of the active marker, in units appropriate
to the current measurement.
13
Marker Stats, Bandwidth. These are statistical marker values that the analyzer
calculates when you access the menus with the
14
Softkey Labels. These menu labels redefine the function of the softkeys that are
MARKER FCTN
key.
located to the right of the analyzer display.
15
Pass/Fail. During limit testing, the result will be annunciated as “PASS” if the
limits are not exceeded, and “FAIL” if any points exceed the limits.
key.
key.
1-7
Getting Started
A Quick Tour
Rear panel
Figure 1-3. Agilent 8702E Rear Panel
1
Serial number plate.
2
External Monitor. Standard VGA video output connector provides analog red,
green, and blue video signals.
3
GPIB connector. This allows you to connect the analyzer to an external
controller, compatible peripherals, and other instruments for an automated
system.
4
PARALLEL connector. This connector allows the analyzer to output to a
peripheral with a parallel input. Also included, is a general purpose input/
output (GPIO) bus that can control eight output bits and read five input bits
through test sequencing.
5
RS-232 connector. This connector allows the analyzer to output to a peripheral
with an RS-232 (serial) input.
6
KEYBOARD input (DIN) connector. This connector allows you to connect an
external keyboard. This provides a more convenient means to enter a title for
storage files, as well as substitute for the analyzer’s front panel keyboard. The
1-8
Getting Started
A Quick Tour
keyboard must be connected to the analyzer before the power is switched on.
7
Power cord receptacle, with fuse.
8
Line voltage selector switch.
9
10 MHZ REFERENCE ADJUST. (Option 1D5)
10
10 MHZ PRECISION REFERENCE OUTPUT. (Option 1D5)
11
EXTERNAL REFERENCE INPUT connector. This allows for a frequency
reference signal input that can phase lock the analyzer to an external frequency
standard for increased frequency accuracy.
12
AUXILIARY INPUT connector. This allows for a dc or ac voltage input from an
external signal source, such as a detector or function generator. The analyzer
can be set to measure the auxillary input from the S-parameter menu.
13
EXTERNAL AM connector. This allows for an external analog signal input that
is applied to the ALC circuitry of the analyzer’s source. This input analog signal
amplitude modulates the RF output signal.
14
EXTERNAL TRIGGER connector. This allows connection of an external
negative-going TTL-compatible signal that will trigger a measurement sweep.
The trigger can be set to external through softkey functions.
15
TEST SEQUENCE. Outputs a TTL signal that can be programmed in a test
sequence to be high or low, or pulse (10 µseconds) high or low at the end of a
sweep for robotic part handler interface.
16
LIMIT TEST. Outputs a TTL signal of the limit test results as follows:
•Pass: TTL high
• Fail: TTL low
17
BIAS INPUTS AND FUSES. These connector bias devices connected to port 1
and port 2. The fuses (1 A, 125 V) protect the port 1 and port 2 bias lines.
18
TEST SET INTERCONNECT. This allows you to connect an Agilent 8702E
Option 011 analyzer to an Agilent 85046A/B or 85047A S-parameter test set
using the interconnect cable supplied with the test set. The S-parameter test
set is then fully controlled by the analyzer.
19
Fan.
20
Measurement Restart. This port is not used.
1-9
Getting Started
A Quick Tour
Figure 1-4. Rear Panel Connectors
1-10
Getting Started
Changing Instrument Settings
Changing Instrument Settings
Once a function is selected by a front-panel key or softkey, it is “active” and its
value is shown in the display’s active function area. Use the numeric keypad,
the knob, and the step keys to change the value of active functions. Generally,
the keypad, knob, and step keys can be used interchangeably. If no other functions are activated, the knob moves the active marker.
You can use the
well as any displayed prompts, error messages, or warnings. Use this function
to clear the display before plotting. This key is also helpful in preventing the
changing of active values by accidentally moving the knob.
Use the ← key to delete the last entry, or the last digit entered from the
numeric keypad.
ENTRY OFF
key to clear and turn off the active entry area, as
Terminating number entries
The units terminator keys are the four keys in the right column of the keypad.
You must use these keys to specify units of numerical entries from the keypad.
A numerical entry is incomplete until a terminator is supplied. The analyzer
indicates that an input is incomplete by a data entry arrow ← pointing at the
last entered digit in the active entry area. When you press the units terminator
key, the arrow is replaced by the units you selected.
Table 1-1. Unit Keys
Key Description
G/n
µ
M/
k/m
x1 basic units: dB, dBm, degrees, seconds, Hz, or dB/GHz (may be used to
Giga/nano (10
Mega/micro (106 / 10–6)
kilo/milli (10
terminate unitless entries, such as averaging factor)
9
/ 10–9)
3
/ 10–3)
1-11
Getting Started
Changing Instrument Settings
Stepping entry values up or down
You can use the step keys ↑ (up) and ↓ (down) to step the current value of the
active function up or down. The analyzer defines the steps for different functions. No units terminator is required.
PRESET
The
key sets the instrument to its default state
As you perform your measurements, remember that you can always return the
Agilent 8702E to its factory default settings by pressing the front-panel
key. Pressing
PRESET
also returns any guided setup settings to their default val-
PRESET
ues. If you leave guided setup by pressing some other key, you can return to
your last guided setup menu by pressing the front-panel
SYSTEM
key.
Two measurements can be displayed simultaneously
The analyzer has two digital channels for independent measurements. You can
view both the active and inactive channel traces, either overlaid or on separate
graticules one above the other (split display). The dual channel and split display features are accessed through the display menus.
The two channels allow you to measure and view two different sets of data
simultaneously. For example, the analyzer can display the reflection and
transmission characteristics of a device, or one measurement with two different frequency spans.
Use the
CHAN 1
and
CHAN 2
keys to select the “active channel.” All of the channel-specific keys that you select apply to the active channel. The current
active channel is indicated by an amber LED adjacent to the corresponding
channel key.
The two channels are normally coupled
Normally, the two channels are coupled. With the
COUPLED CH ON off
key set to
on (the preset condition), both channels have the same stimulus values (the
inactive channel takes on the stimulus values of the active channel).
1-12
Getting Started
Changing Instrument Settings
In the stimulus coupled mode, the following parameters are coupled:
•frequency
• number of points
• source power
• number of groups
• power slope
• IF bandwidth
• sweep time
• trigger type
• gating parameters
• sweep type
• harmonic measurement
• power meter calibration
You can uncouple the stimulus values between the two display channels by
pressing
COUPLED CH ON off
. This allows you to assign different stimulus values
for each channel; it’s almost like having the use of a second analyzer. The coupling and uncoupling of the stimulus values for the two channels is independent
of the display and marker functions.
Coupling of stimulus values for the two channels is independent of
on OFF
in the display menu and
MARKERS: UNCOUPLED
in the marker mode menu.
DUAL CHAN
Measurement markers can have the same stimulus values (coupled) for the two
channels, or they can be uncoupled for independent control in each channel.
COUPLED CH on OFF
becomes an alternate sweep function when dual channel display is on; in this mode the analyzer alternates between the two sets of stimulus
values for measurement of data and both are displayed.
1-13
Getting Started
Making Measurements Using Guided Setup
Making Measurements Using Guided Setup
In this section, you’ll learn how to make fast, easy measurements using the
Agilent 8702E’s guided setup feature. When you first turn on the instrument
or press the green
GUIDED SETUP
press
Guided setups contain the instructions you need to perform accurate measurements including:
• Diagrams of equipment connections.
• RF source’s start frequency, stop frequency, and power level.
•Calibration.
PRESET
key, the
and follow the displayed instructions.
GUIDED SETUP
softkey is displayed. Simply
The first step in the procedure is to select either
REFLECTION
the following four types of devices to measure:
• E/E (electrical device)
• E/O (lightwave source)
• O/E (lightwave receiver)
• O/O (optical device)
With reflection measurements, you select the type of port that you are characterizing on your device:
• 1-PORT ELECTRICAL
•1-PORT OPTICAL
In guided setups, always press
This section provides step-by-step instructions for characterizing an O/E
device. Because all of the guided setup procedures are similar, after performing this procedure you should be able to perform any of the other procedures.
You’ll need Agilent 83400-series lightwave sources and receivers
For any measurements other than E/E or 1-PORT ELECTRICAL, you’ll need
Agilent 83400-series lightwave sources and receivers to provide modulation
and demodulation of the light signal. These sources and receivers come with
measurements. With bandwidth measurements, you select one of
CONTINUE
to display the next set of instructions.
BANDWIDTH
(transmission) or
1-14
Getting Started
Making Measurements Using Guided Setup
calibration data that is stored on a 3.5 inch diskette. During a guided setup
procedure, you will be prompted to insert the disk into the Agilent 8702E’s
front-panel disk drive in order to read the calibration data.
Calibration improves measurement accuracy
An important part of making measurements, including those in guided setups,
is performing a calibration. Calibration removes certain repeatable errors from
your measurements that are associated with the test setup. During guided
setup procedures, you will perform a
corrects for the test setup’s frequency response. During E/O and O/E procedures you can choose to perform a
calibration is more accurate but requires several additional steps. A
& MATCH
This involves temporarily disconnecting the source or receiver and measuring
open, short, and load calibration standards.
You’ll need an Agilent calibration kit
Agilent Technologies calibration kits include the open, short, and load
required to make
Agilent 83400 substitution during calibration
Whenever you’re characterizing an E/O or O/E device, the calibration is performed after temporarily substituting an Agilent 83400 source or receiver for
the device you’re testing. After the calibration has completed, your device is
re-inserted into the test setup, and the measurement is performed. For example, suppose that you want to measure the bandpass of an E/O device. You
first connect the test setup using your device and an Agilent 83400-series
lightwave receiver. During the first part of the guided setup procedure, you’ll
set the measurement parameters. Then during calibration, you’ll remove your
device and substitute an Agilent 83400-series lightwave source. After the calibration is complete, the procedure prompts you to remove the Agilent 83400series lightwave source and re-insert your test device.
calibration characterizes the test setup at the measurement plane.
RESPONSE & MATCH
RESPONSE
RESPONSE & MATCH
calibrations during measurements.
calibration. This calibration
calibration instead. This
RESPONSE
To make an O/E measurement
This step-by-step procedure takes you through the measurement of a typical
O/E device. During the procedure, you’ll perform a
tion. If your device requires different measurement parameters (for example,
the start frequency), simply change them as needed.
In order to perform this procedure, you’ll need an Agilent 83400-series lightwave receiver with its calibration data disk, a lightwave source, an Agilent
Technologies calibration kit, and a receiver that you want to characterize.
RESPONSE & MATCH
calibra-
1-15
Getting Started
Making Measurements Using Guided Setup
1
Connect the test equipment as shown in the following figure.
Figure 1-5. Initial test setup
2
3
4
5
PRESET
Press
Press
Press
Use the
to set the instrument to its default condition.
GUIDED SETUP, BANDWIDTH
O/E, CONTINUE,
START
and
and then
STOP
modulation. Then, press
NUMBER OF POINTS
The
softkey allows you to change the number of measure-
, and then
CONTINUE
CONTINUE
.
.
softkeys to enter the frequency limits for the
CONTINUE
.
ment points taken during each sweep. The default setting is normally adequate for most measurements.
6
Use the
CONTINUE
Use the
RF SOURCE POWER
.
SWEEP TIME
softkey to decrease the sweep time if needed. Although
softkey to set the power level, and then press
this results in faster measurements, sweeps that are too fast will distort the
displayed response. If this happens, increase the sweep time until changes no
longer effect the displayed trace.
7
RESPONSE & MATCH
Press
1-16
to select the most extensive calibration procedure.
Getting Started
Making Measurements Using Guided Setup
Because you are performing the additional electrical match calibration, you
will need a calibration kit which includes open, short, and load calibration
standards.
8
9
CAL KIT
Press
PRIOR MENU
DEFINE RECEIVER
Press
, and select the calibration kit that you will be using. Then press
.
. Insert the calibration disk that came with the
Agilent 83400-series lightwave receiver into the Agilent 8702E’s front-panel
disk drive.
10
11
LOAD DISK CAL DATA
Press
RCVR1 DISK
. Then press
, and when the data is finished loading, press
CONTINUE
.
Disconnect the RF cable from the input to the lightwave source. If an adapter
is needed to make the RF thru connection described in Step 13, it should be
connected between the RF cable and the open, short, and load.Connect the
“open” connector from the calibration kit. Step through the menus measuring
the open, short, and broadband (load). For the remainder of the test, do not
disconnect the cable from the Agilent 8702E. Refer to Figure 1-6 on page 1-18.
12
Disconnect the RF cable from the output of the lightwave receiver. Connect the
“open” connector from the calibration kit. Step through the menus measuring
the open, short, and broadband (load). For the remainder of the test, do not
disconnect the cable from the Agilent 8702E.
13
Use an RF “through” connector to connect the two RF cables together. Press
RF THRU
14
Connect the lightwave source and lightwave receiver as shown on the
and then
DONE: RF THRU
.
Agilent 8702E’s display. Refer to Figure 1-7 on page 1-18.
LOAD
1-17
Getting Started
Making Measurements Using Guided Setup
Figure 1-6. Match calibration
Figure 1-7. Calibration with lightwave receiver
15
16
Press
Press
1-18
RECEIVER
DISK (1)
and then
and then
DONE RECEIVER
DONE: SRC + RCVR
.
.
17
Is the noise floor higher than the crosstalk?
Getting Started
Making Measurements Using Guided Setup
•Yes—press
OMIT ISOLATION
, and then press
DONE: ISOL’N STD
.
• No—disconnect the fiber-optic cable from the lightwave source’s output
connector, and press
DONE: ISOL’N STD
press
ISOLN LOAD
.
. Reconnect the fiber-optic cable, and then
• If you are not sure, then omit isolation.
18
Remove the Agilent 83400-series lightwave receiver, and replace it with the
receiver that you want to test.
Figure 1-8. Final setup for measurements
19
Press
VIEW MEASURE
. The bandpass measurement of your receiver is shown on
the display.
1-19
Getting Started
Setting the RF Output
Setting the RF Output
The stimulus function block keys are used to define the source RF output signal to the test device by providing control of the following parameters:
• swept frequency ranges
• time domain start and stop times
• RF power level and power ranges
• channel and test port coupling
• sweep time
• sweep type
• number of data points
• sweep trigger
The SWEEP SETUP key provides the series of menus which are used to define
and control all stimulus functions other than start, stop, center, and span.
When the SWEEP SETUP key is pressed, the stimulus menu is displayed.
The stimulus menu is used to specify the sweep time, number of measurement
points per sweep, and CW frequency. It includes the capability to couple or
uncouple the stimulus functions of the two display channels, and the measurement restart function. In addition, it leads to other softkey menus that define
power level, trigger type, and sweep type.
Defining the frequency range
START, STOP, CENTER,
The
or other horizontal axis range of the stimulus. The range can be expressed as
either start/stop or center/span. When one of these keys is pressed, its function becomes the active function. The value is displayed in the active entry
area and can be changed with the knob, step keys, or numeric keypad. Current
stimulus values for the active channel are also displayed along the bottom of
the graticule. Frequency values can be blanked for security purposes, using
the display menus.
1-20
and
SPAN
keys are used to define the frequency range
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