Page 1
R&S®FSV/A3000 I/Q Analyzer
and I/Q Input Interfaces
User Manual
(;ÜãT2)
1178853602
Version 10
Page 2
This manual applies to the following R&S®FSV3000 and R&S®FSVA3000 models with firmware version
1.90 and higher:
●
R&S®FSV3004 (1330.5000K04) / R&S®FSVA3004 (1330.5000K05)
●
R&S®FSV3007 (1330.5000K07) / R&S®FSVA3007 (1330.5000K08)
●
R&S®FSV3013 (1330.5000K13) / R&S®FSVA3013 (1330.5000K14)
●
R&S®FSV3030 (1330.5000K30) / R&S®FSVA3030 (1330.5000K31)
●
R&S®FSV3044 (1330.5000K43) / R&S®FSVA3044 (1330.5000K44)
●
R&S®FSV3050 (1330.5000K50) / R&S®FSVA3050 (1330.5000K51)
In addition to the base unit, the following options are described:
●
R&S®FSV3-B4, OCXO (1330.3794.02)
●
R&S®FSV3-B5, Additional Interfaces (1330.3365.02/1330.3407.02)
●
R&S®FSV3-B10, external generator control (1330.3859.02)
●
R&S®FSV3-B13, high-pass filter (1313.0761.02)
●
R&S®FSV3-B24, preamplifier (1330.4049.XX)
●
R&S®FSV3-B25, electronic attenuator (1330.4078.02)
●
R&S®FSV3-B40, 40 MHz analysis bandwidth extension (1330.4103.02)
●
R&S®FSV3-B114, Enhanced computing power (1330.4910.02)
●
R&S®FSV3-B200, 200 MHz analysis bandwidth extension (1330.4132.02)
●
R&S®FSV3-B400, 400 MHz analysis bandwidth extension (1330.7154.02) / R&S®FSV3-U400
(1330.7183.02)
●
R&S®FSV3-B600, 600 MHz analysis bandwidth extension (1346.5004.02)
●
R&S®FSV3-B1000, 1 GHz analysis bandwidth extension (1346.3699.02)
© 2022 Rohde & Schwarz GmbH & Co. KG
Muehldorfstr. 15, 81671 Muenchen, Germany
Phone: +49 89 41 29 - 0
Email: info@rohde-schwarz.com
Internet: www.rohde-schwarz.com
Subject to change – data without tolerance limits is not binding.
R&S® is a registered trademark of Rohde & Schwarz GmbH & Co. KG.
All other trademarks are the properties of their respective owners.
1178.8536.02 | Version 10 | R&S®FSV/A3000 I/Q Analyzer
Throughout this manual, products from Rohde & Schwarz are indicated without the ® symbol, e.g. R&S®FSV/A3000 is indicated as
R&S FSV/A3000 and refers to both the R&S FSV3000 and the R&S FSVA3000. Products of the R&S®SMW family, e.g.
R&S®SMW200A, are indicated as R&S SMW.
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R&S®FSV/A3000 I/Q Analyzer
Contents
1 Documentation overview.......................................................................7
1.1 Getting started manual................................................................................................. 7
1.2 User manuals and help.................................................................................................7
1.3 Service manual..............................................................................................................8
1.4 Instrument security procedures.................................................................................. 8
1.5 Printed safety instructions...........................................................................................8
1.6 Data sheets and brochures.......................................................................................... 8
1.7 Release notes and open-source acknowledgment (OSA).........................................8
1.8 Application notes, application cards, white papers, etc........................................... 9
2 Welcome to the I/Q Analyzer application...........................................10
Contents
2.1 Starting the I/Q Analyzer application........................................................................ 10
2.2 Understanding the display information.................................................................... 11
3 Measurement and result displays...................................................... 14
4 Basics on I/Q data acquisition and processing................................ 19
4.1 Processing analog I/Q data from RF input............................................................... 19
4.2 Using probes............................................................................................................... 25
4.3 Basics on external mixers..........................................................................................28
4.4 Basics on external generator control........................................................................33
4.5 Basics on input from I/Q data files............................................................................ 43
4.6 IF and video signal output..........................................................................................45
4.7 Receiving and providing trigger signals...................................................................45
4.8 Basics on FFT..............................................................................................................46
5 Configuration........................................................................................53
5.1 Configuration overview.............................................................................................. 53
5.2 Import/export functions..............................................................................................55
5.3 Data input and output settings.................................................................................. 59
5.4 Amplitude.....................................................................................................................92
5.5 Frequency settings..................................................................................................... 98
5.6 Trigger settings........................................................................................................... 99
5.7 Data acquisition and bandwidth settings............................................................... 106
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R&S®FSV/A3000 I/Q Analyzer
5.8 Display configuration................................................................................................114
5.9 Adjusting settings automatically............................................................................. 114
6 Analysis...............................................................................................119
6.1 Trace settings............................................................................................................ 119
6.2 Spectrogram settings............................................................................................... 124
6.3 Trace / data export configuration............................................................................ 129
6.4 Marker usage............................................................................................................. 133
7 I/Q data import and export................................................................ 161
7.1 Export functions........................................................................................................161
8 How to work with I/Q data................................................................. 166
8.1 How to perform measurements in the I/Q Analyzer application...........................166
8.2 How to export and import I/Q data.......................................................................... 166
Contents
9 Remote commands to perform measurements with I/Q data........ 169
9.1 Introduction............................................................................................................... 169
9.2 Common suffixes...................................................................................................... 174
9.3 Activating I/Q Analyzer measurements...................................................................175
9.4 Configuring I/Q Analyzer measurements................................................................180
9.5 Configuring the result display................................................................................. 277
9.6 Capturing data and performing sweeps................................................................. 285
9.7 I/Q Analysis................................................................................................................291
9.8 Retrieving results......................................................................................................350
9.9 Importing and exporting I/Q data and results........................................................ 362
9.10 Programming examples........................................................................................... 364
9.11 Deprecated commands.............................................................................................366
Annex.................................................................................................. 368
A Formats for returned values: ASCII format and binary format...... 369
B Reference: format description for I/Q data files..............................370
C Reference: supported I/Q file formats..............................................372
C.1 I/Q data file format (iq-tar)........................................................................................ 373
C.2 CSV file format.......................................................................................................... 381
C.3 IQW file format...........................................................................................................384
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R&S®FSV/A3000 I/Q Analyzer
C.4
Matlab® v. 4 / v. 7.3 file format.................................................................................. 385
C.5 AID format..................................................................................................................388
C.6 WV format.................................................................................................................. 398
List of commands (I/Q Analyzer)...................................................... 399
Index....................................................................................................408
Contents
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R&S®FSV/A3000 I/Q Analyzer
Contents
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R&S®FSV/A3000 I/Q Analyzer
1 Documentation overview
This section provides an overview of the R&S FSV/A user documentation. Unless
specified otherwise, you find the documents at:
www.rohde-schwarz.com/manual/FSVA3000
www.rohde-schwarz.com/manual/FSV3000
Further documents are available at:
www.rohde-schwarz.com/product/FSVA3000
www.rohde-schwarz.com/product/FSV3000
1.1 Getting started manual
Introduces the R&S FSV/A 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.
Documentation overview
User manuals and help
A printed version is delivered with the instrument. A PDF version is available for download on the Internet.
1.2 User 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 FSV/A is
not included.
The contents of the user manuals are available as help in the R&S FSV/A. 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.
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R&S®FSV/A3000 I/Q Analyzer
1.3 Service manual
Describes the performance test for checking the rated specifications, module replacement and repair, firmware update, troubleshooting and fault elimination, and contains
mechanical drawings and spare part lists.
The service manual is available for registered users on the global Rohde & Schwarz
information system (GLORIS):
R&S®FSVA3000/FSV3000 Service manual
1.4 Instrument security procedures
Deals with security issues when working with the R&S FSV/A in secure areas. It is
available for download on the Internet.
Documentation overview
Release notes and open-source acknowledgment (OSA)
1.5 Printed safety instructions
Provides safety information in many languages. The printed document is delivered with
the product.
1.6 Data sheets and brochures
The data sheet contains the technical specifications of the R&S FSV/A. 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/FSV3000 /
www.rohde-schwarz.com/brochure-datasheet/FSVA3000
1.7 Release 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 software makes use of several valuable open source software packages. An opensource acknowledgment document provides verbatim license texts of the used open
source software.
See www.rohde-schwarz.com/firmware/FSV3000 /
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R&S®FSV/A3000 I/Q Analyzer
www.rohde-schwarz.com/firmware/FSVA3000
1.8 Application notes, application cards, white papers, etc.
These documents deal with special applications or background information on particular topics.
See www.rohde-schwarz.com/application/FSV3000 /
www.rohde-schwarz.com/application/FSVA3000
Documentation overview
Application notes, application cards, white papers, etc.
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R&S®FSV/A3000 I/Q Analyzer
2 Welcome to the I/Q Analyzer application
The R&S FSV3 I/Q Analyzer is a firmware application that adds functionality to perform
I/Q data acquisition and analysis to the R&S FSV/A.
The R&S FSV3 I/Q Analyzer features:
●
Acquisition of analog I/Q data
●
Import of stored I/Q data from other applications
●
Spectrum, magnitude, I/Q vector and separate I and Q component analysis of any
I/Q data on the instrument
●
Export of I/Q data to other applications
This user manual contains a description of the functionality that the application provides, including remote control operation.
All functions not discussed in this manual are the same as in the base unit and are
described in the R&S FSV/A User Manual. The latest version is available for download
at the product homepage http://www.rohde-schwarz.com/product/FSVA3000.
Welcome to the I/Q Analyzer application
Starting the I/Q Analyzer application
Additional information
Several application notes discussing I/Q analysis are available from the Rohde &
Schwarz website:
1EF85: Converting R&S I/Q data files
1EF92: Wideband Signal Analysis
1MA257: Wideband mm-Wave Signal Generation and Analysis
1EF84: Differential measurements with Spectrum Analyzers and Probes
Installation
The R&S FSV3 I/Q Analyzer application is part of the standard base unit and requires
no further installation.
2.1 Starting the I/Q Analyzer application
The I/Q Analyzer is an application on the R&S FSV/A.
To activate the I/Q Analyzer application
1. Select the [MODE] key.
A dialog box opens that contains all applications currently available on your
R&S FSV/A.
2. Select the "I/Q Analyzer" item.
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R&S®FSV/A3000 I/Q Analyzer
The R&S FSV/A opens a new channel for the I/Q Analyzer application.
The measurement is started immediately with the default settings.
It can be configured in the I/Q Analyzer "Overview" dialog box, which is displayed
when you select the "Overview" softkey from any menu (see Chapter 5.1, "Configura-
tion overview", on page 53).
Multiple Channels and Sequencer Function
When you activate an application, a new channel is created which determines the
measurement settings for that application (channel). The same application can be activated with different measurement settings by creating several channels for the same
application.
The number of channels that can be configured at the same time depends on the available memory on the instrument.
Welcome to the I/Q Analyzer application
Understanding the display information
Only one measurement can be performed at any time, namely the one in the currently
active channel. However, in order to perform the configured measurements consecutively, a Sequencer function is provided.
If activated, the measurements configured in the currently defined channels 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 channels 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.
For details on the Sequencer function see the R&S FSV/A User Manual.
symbol in the tab label.
2.2 Understanding the display information
The following figure shows a measurement diagram during I/Q Analyzer operation. All
different information areas are labeled. They are explained in more detail in the following sections.
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R&S®FSV/A3000 I/Q Analyzer
1 2 3 4
Welcome to the I/Q Analyzer application
Understanding the display information
56
Figure 2-1: Screen elements in the I/Q Analyzer application
1+4 = Window title bar with diagram-specific (trace) information
2 = Channel bar for firmware and measurement settings
3 = Diagram area
5 = Diagram footer with diagram-specific information, depending on result display
6 = Instrument status bar with error messages and date/time display
Channel bar information
In the I/Q Analyzer application, the R&S FSV/A shows the following settings:
Table 2-1: Information displayed in the channel bar for the I/Q Analyzer application
Ref Level Reference level
(m.+el.)Att (Mechanical and electronic) RF attenuation
Ref Offset Reference level offset
Freq Center frequency
Meas Time Measurement time
Rec Length Defined record length (number of samples to capture)
SRate Defined sample rate for data acquisition
RBW (Spectrum evaluation only) Resolution bandwidth calculated from the
sample rate and record length
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In addition, the channel bar also displays information on instrument settings that affect
the measurement results even though this is not immediately apparent from the display
of the measured values (e.g. transducer or trigger settings). This information is displayed only when applicable for the current measurement.
For details see the R&S FSV/A Getting Started manual.
Window title bar information
For each diagram, the header provides the following information:
Welcome to the I/Q Analyzer application
Understanding the display information
4
1 2 3
Figure 2-2: Window title bar information in the I/Q Analyzer application
1 = Window number
2 = Window type
3 = Trace color
4 = Trace number
5 = Detector
6 = Trace mode
5 6
Diagram footer information
The information in the diagram footer (beneath the diagram) depends on the evaluation:
●
Center frequency
●
Number of sweep points
●
Range per division (x-axis)
●
Span (Spectrum)
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.
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R&S®FSV/A3000 I/Q Analyzer
3 Measurement and result displays
Access: "Overview" > "Display Config"
Or: [MEAS] > "Display Config"
The I/Q Analyzer can capture I/Q data. The I/Q data that was captured by or imported
to the R&S FSV/A can then be evaluated in various different result displays. Select the
result displays using the SmartGrid functions.
Up to 6 evaluations can be displayed in the I/Q Analyzer at any time, including several
graphical diagrams, marker tables or peak lists.
For details on working with the SmartGrid see the R&S FSV/A Getting Started manual.
Measurements in the time and frequency domain
The time and frequency domain measurements and the available results are described
in detail in the R&S FSV/A User Manual.
Measurement and result displays
Result displays for I/Q data:
Magnitude..................................................................................................................... 14
Spectrum.......................................................................................................................15
I/Q-Vector......................................................................................................................15
Real/Imag (I/Q)..............................................................................................................16
Phase vs. Time..............................................................................................................16
Marker Table................................................................................................................. 17
Marker Peak List........................................................................................................... 17
Magnitude
Shows the level values in time domain.
Remote command:
LAY:ADD:WIND? '1',RIGH,MAGN, see LAYout:ADD[:WINDow]? on page 278
Results:
TRACe<n>[:DATA]? on page 355
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R&S®FSV/A3000 I/Q Analyzer
Spectrum
Displays the frequency spectrum of the captured I/Q samples.
Measurement and result displays
Remote command:
LAY:ADD:WIND? '1',RIGH,FREQ, see LAYout:ADD[:WINDow]? on page 278
Results:
TRACe<n>[:DATA]? on page 355
I/Q-Vector
Displays the captured samples in an I/Q-plot. The samples are connected by a line.
Note: For the I/Q vector result display, the number of I/Q samples to record ("Record
Length") must be identical to the number of trace points to be displayed ("Sweep
Points"; for I/Q Analyzer: 10001). For record lengths outside the valid range of sweep
points the diagram does not show valid results.
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R&S®FSV/A3000 I/Q Analyzer
Remote command:
LAY:ADD:WIND? '1',RIGH,VECT, see LAYout:ADD[:WINDow]? on page 278
Results:
TRACe<n>[:DATA]? on page 355
Real/Imag (I/Q)
Displays the I and Q values in separate diagrams.
Measurement and result displays
Remote command:
LAY:ADD:WIND? '1',RIGH,RIM, see LAYout:ADD[:WINDow]? on page 278
Results:
TRACe<n>[:DATA]? on page 355
Phase vs. Time
Shows the phase values in the time domain.
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R&S®FSV/A3000 I/Q Analyzer
Measurement and result displays
Remote command:
LAY:ADD? '1',RIGH, PHASe, see LAYout:ADD[:WINDow]? on page 278
Marker Table
Displays a table with the current marker values for the active markers.
This table is displayed automatically if configured accordingly.
Tip: To navigate within long marker tables, simply scroll through the entries with your
finger on the touchscreen.
Remote command:
LAY:ADD? '1',RIGH, MTAB, see LAYout:ADD[:WINDow]? on page 278
Results:
CALCulate<n>:MARKer<m>:X on page 313
CALCulate<n>:MARKer<m>:Y? on page 361
Marker Peak List
The marker peak list determines the frequencies and levels of peaks in the spectrum or
time domain. How many peaks are displayed can be defined, as well as the sort order.
In addition, the detected peaks can be indicated in the diagram. The peak list can also
be exported to a file for analysis in an external application.
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R&S®FSV/A3000 I/Q Analyzer
Tip: To navigate within long marker peak lists, simply scroll through the entries with
your finger on the touchscreen.
Remote command:
LAY:ADD? '1',RIGH, PEAK, see LAYout:ADD[:WINDow]? on page 278
Results:
CALCulate<n>:MARKer<m>:X on page 313
CALCulate<n>:MARKer<m>:Y? on page 361
Measurement and result displays
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R&S®FSV/A3000 I/Q Analyzer
4 Basics on I/Q data acquisition and process-
ing
Some background knowledge on basic terms and principles used when describing I/Q
data acquisition on the R&S FSV/A in general, and in the I/Q Analyzer application in
particular, is provided here for a better understanding of the required configuration settings.
The I/Q Analyzer provides various possibilities to acquire the I/Q data to be analyzed:
●
Capturing analog I/Q data from the "RF Input" connector
●
Importing I/Q data from a file
Background information for all these scenarios and more is provided in the following
sections.
● Processing analog I/Q data from RF input..............................................................19
● Using probes...........................................................................................................25
● Basics on external mixers....................................................................................... 28
● Basics on external generator control.......................................................................33
● Basics on input from I/Q data files.......................................................................... 43
● IF and video signal output.......................................................................................45
● Receiving and providing trigger signals.................................................................. 45
● Basics on FFT.........................................................................................................46
Basics on I/Q data acquisition and processing
Processing analog I/Q data from RF input
4.1 Processing analog I/Q data from RF input
Complex baseband data
In the telephone systems of the past, baseband data was transmitted unchanged as an
analog signal. In modern phone systems and in radio communication, however, the
baseband data is modulated on a carrier frequency, which is then transmitted. The
receiver must demodulate the data based on the carrier frequency. When using modern modulation methods (e.g. QPSK, QAM etc.), the baseband signal becomes complex. Complex data (or: I/Q data) consists of an imaginary (I) and a real (Q) component.
Sweep vs sampling
The standard Spectrum application on the R&S FSV/A performs frequency sweeps on
the input signal and measurements in the frequency and time domain. Other applications on the R&S FSV/A, such as the I/Q Analyzer, sample and process the individual I
and Q components of the complex signal.
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R&S®FSV/A3000 I/Q Analyzer
I/Q Analyzer - processing complex data from RF input
The I/Q Analyzer is a standard application used to capture and analyze I/Q data on the
R&S FSV/A. By default, it assumes the I/Q data is modulated on a carrier frequency
and input via the "RF Input" connector on the R&S FSV/A.
The A/D converter samples the IF signal at a rate of 200 MHz. The digital signal is
down-converted to the complex baseband, lowpass-filtered, and the sample rate is
reduced. The analog filter stages in the analyzer cause a frequency response which
adds to the modulation errors. An equalizer filter before the resampler compensates
for this frequency response. The continuously adjustable sample rates are realized
using an optimal decimation filter and subsequent resampling on the set sample rate.
A dedicated memory (capture buffer) is available in the R&S FSV/A for a maximum of
400 Msamples (400*1000*1000) of complex samples (pairs of I and Q data). The number of complex samples to be captured can be defined (for restrictions refer to Chap-
ter 4.1.1, "Sample rate and maximum usable I/Q bandwidth for RF input",
on page 20).
The block diagram in Figure 4-1 shows the analyzer hardware from the IF section to
the processor.
Basics on I/Q data acquisition and processing
Processing analog I/Q data from RF input
Figure 4-1: Block diagram illustrating the R&S FSV/A signal processing for analog I/Q data (without
bandwidth extension options)
4.1.1 Sample rate and maximum usable I/Q bandwidth for RF input
Definitions
●
Input sample rate (ISR): the sample rate of the useful data provided by the device
connected to the input of the R&S FSV/A
●
(User, Output) Sample rate (SR): the user-defined sample rate (e.g. in the "Data
Acquisition" dialog box in the "I/Q Analyzer" application) which is used as the basis
for analysis or output
●
Usable I/Q (Analysis) bandwidth: the bandwidth range in which the signal
remains undistorted in regard to amplitude characteristic and group delay; this
range can be used for accurate analysis by the R&S FSV/A
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R&S®FSV/A3000 I/Q Analyzer
●
Record length: Number of I/Q samples to capture during the specified measurement time; calculated as the measurement time multiplied by the sample rate
For the I/Q data acquisition, digital decimation filters are used internally in the
R&S FSV/A. The passband of these digital filters determines the maximum usable I/Q
bandwidth. In consequence, signals within the usable I/Q bandwidth (passband)
remain unchanged, while signals outside the usable I/Q bandwidth (passband) are
suppressed. Usually, the suppressed signals are noise, artifacts, and the second IF
side band. If frequencies of interest to you are also suppressed, try to increase the output sample rate, which increases the maximum usable I/Q bandwidth.
Bandwidth extension options
You can extend the maximum usable I/Q bandwidth provided by the R&S FSV/A in the
basic installation by adding options. These options can either be included in the initial
installation (B-options) or updated later (U-options). The maximum bandwidth provided
by the individual option is indicated by its number, for example, B40 extends the bandwidth to 40 MHz.
Note that the U-options as of U40 always require all lower-bandwidth options as a prerequisite, while the B-options already include them.
Basics on I/Q data acquisition and processing
Processing analog I/Q data from RF input
As a rule, the usable I/Q bandwidth is proportional to the output sample rate. Yet, when
the I/Q bandwidth reaches the bandwidth of the analog IF filter (at very high output
sample rates), the curve breaks.
● Bandwidth extension options.................................................................................. 21
● Relationship between sample rate, record length and usable I/Q bandwidth......... 21
● R&S FSV/A without additional bandwidth extension options.................................. 22
● R&S FSV/A with I/Q bandwidth extension option B40 or U40................................ 23
● R&S FSV/A with I/Q bandwidth extension option B200.......................................... 24
● R&S FSV/A with I/Q bandwidth extension option B400.......................................... 24
● R&S FSV/A with I/Q bandwidth extension option B600.......................................... 24
● R&S FSV/A with I/Q bandwidth extension option B1000........................................ 24
4.1.1.1 Bandwidth extension options
Max. usable I/Q BW Required B-option Required U-options
40 MHz B40
200 MHz B200
400 MHz B400 B200+U400
600 MHz B600
1000 MHz B1000 B600+U1006
4.1.1.2 Relationship between sample rate, record length and usable I/Q bandwidth
Up to the maximum bandwidth, the following rule applies:
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R&S®FSV/A3000 I/Q Analyzer
Usable I/Q bandwidth = 0.8 * Output sample rate
Regarding the record length, the following rule applies:
Record length = Measurement time * sample rate
Maximum record length for RF input
The absolute maximum record length (AbsMaxRecordLength), that is, the maximum
number of samples that can be captured, is 100 Msamples (with option B114:
800 Msamples).
When using bandwidth extension options R&S FSV3-B600/-B1000, the maximum
record length depends on the analysis bandwidth.
Table 4-1: Maximum record length with I/Q bandwidth extension option B600/B1000
Basics on I/Q data acquisition and processing
Processing analog I/Q data from RF input
Analysis bandwidth *)
80 Hz to 400 MHz <Capture-
400 MHz to
800 MHz
(B600: 400 MHz to
600 MHz)
>800 MHz to 1000
MHz
*) If you restrict the maximum bandwidth to 40 MHz, 200 MHz, or 400 MHz manually ("Maximum Band-
width" on page 108), the maximum record length is AbsMaxRecordLength.
Max. meas time Maximum record length
AbsMaxRecordLength
Length> /
<SampleRate>
<CaptureLength> /
<SampleRate>
with B114:
819.2 ms
<CaptureLength> /
<SampleRate>
with B114:
409.6 ms
AbsMaxRecordLength * <SampleRate> / (1024*106)
For sample rates ≥2048 MHz: AbsMaxRecordLength
AbsMaxRecordLength * <SampleRate> / (2048*106)
For sample rates ≥2048 MHz: AbsMaxRecordLength
4.1.1.3 R&S FSV/A without additional bandwidth extension options
Sample rate: 100 Hz - 10 GHz
Maximum I/Q bandwidth: 28 MHz
Table 4-2: Maximum I/Q bandwidth
Sample rate Maximum I/Q bandwidth
100 Hz to 35 MHz Proportional up to maximum 28 MHz
35 MHz to 10 GHz 28 MHz
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Usable I/Q
Bandwidth [MHz]
Basics on I/Q data acquisition and processing
Processing analog I/Q data from RF input
28
21
14
7
5
Figure 4-2: Relationship between maximum usable I/Q bandwidth and output sample rate without
bandwidth extensions
RF-Input:
BW = 0.80 * f
out
...
353025201510
25
Without BW
extension options
Output sample
10000
rate f
out
[MHz]
I/Q bandwidths for RF input
Usable I/Q
Bandwidth [MHz]
Activated option
1000
900
800
700
600
500
400
300
200
100
40
50
125
RF-Input:
BW = 0.80 * f
out
...
1250
11251000875750625500375250
B1000
Activated option
B600
Activated option
B400
Activated option
B200
Activated option
B40
Output sample
10000
rate f
out
[MHz]
Figure 4-3: Relationship between maximum usable I/Q bandwidth and output sample rate with
optional bandwidth extensions
4.1.1.4 R&S FSV/A with I/Q bandwidth extension option B40 or U40
Sample rate: 100 Hz - 10 GHz
Maximum bandwidth: 40 MHz
Sample rate Maximum I/Q bandwidth
100 Hz to 50 MHz Proportional up to maximum 40 MHz
50 MHz to 10 GHz 40 MHz
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4.1.1.5 R&S FSV/A with I/Q bandwidth extension option B200
Sample rate: 100 Hz - 10 GHz
Maximum bandwidth: 200 MHz
Sample rate Maximum I/Q bandwidth
100 Hz to 250 MHz Proportional up to maximum 200 MHz
250 MHz to 10 GHz 200 MHz
4.1.1.6 R&S FSV/A with I/Q bandwidth extension option B400
Sample rate: 100 Hz - 10 GHz
Maximum bandwidth: 400 MHz
Sample rate Maximum I/Q bandwidth
100 Hz to 500 MHz Proportional up to maximum 400 MHz
Basics on I/Q data acquisition and processing
Processing analog I/Q data from RF input
500 MHz to 10 GHz 400 MHz
4.1.1.7 R&S FSV/A with I/Q bandwidth extension option B600
Sample rate: 100 Hz - 10 GHz
Maximum bandwidth: 600 MHz
Note that using the bandwidth extension option R&S FSV3-B600, an I/Q bandwidth
larger than 400 MHz is only available for frequency ranges above 7.5 GHz.
Center frequency Sample rate Maximum I/Q bandwidth
≤7.5 GHz 100 Hz to 500 MHz Proportional up to maximum 400 MHz
500 MHz to 10 GHz 400 MHz
>7.5 GHz 100 Hz to 750 MHz Proportional up to maximum 600 MHz
750 MHz to 10 GHz 600 MHz
4.1.1.8 R&S FSV/A with I/Q bandwidth extension option B1000
Sample rate: 100 Hz - 10 GHz
Maximum bandwidth: 1000 MHz
Note that using the bandwidth extension option R&S FSV3-B1000, an I/Q bandwidth
larger than 400 MHz is only available for frequency ranges above 7.5 GHz.
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Center frequency Sample rate Maximum I/Q bandwidth
≤7.5 GHz 100 Hz to 500 MHz Proportional up to maximum 400 MHz
>7.5 GHz 100 Hz to 1250 MHz Proportional up to maximum 1000 MHz
4.2 Using probes
Probes allow you to perform voltage measurements very flexibly and precisely on all
sorts of devices to be tested, without interfering with the signal. The R&S FSV/A base
unit and some (optional) applications support input from probes.
Active modular probes can be connected to the "RF Input" connector on the
R&S FSV/A using an R&S RT-ZA9 adapter. Thus, you can perform frequency sweeps
on data from all active probes directly on the RF input up to the maximum frequency of
the probe and analyzer. The R&S RT-ZA9 provides an interface between the probe's
BNC socket and the analyzer's N-socket. The USB connection provides the necessary
supply voltages for the probe. RF probes are supported by all R&S FSV/A applications,
in particular the Spectrum application.
Basics on I/Q data acquisition and processing
Using probes
500 MHz to 10 GHz 400 MHz
1250 MHz to 10 GHz 1000 MHz
Active probes
When using active probes from the R&S RT family, consider the following:
●
Active probes require operating power from the instrument and have a proprietary
interface to the instrument.
●
The probe is automatically recognized by the instrument, no adjustment is
required.
●
Connections should be as short as possible to keep the usable bandwidth high.
●
Observe the operating voltage range.
Microbutton action
You can define an action to be performed by the R&S FSV/A when the probe's microbutton (if available) is pressed. Currently, a single data acquisition via the probe can be
performed simply by pressing the microbutton.
4.2.1 RF probes
To connect an active probe to the RF Input
1. Connect the R&S RT-ZA9 adapter to the RF Input connector on the R&S FSV/A.
2. Connect the R&S RT-ZA9 adapter's USB cable to a USB connector on the
R&S FSV/A.
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3. Connect the probe to the adapter.
Basics on I/Q data acquisition and processing
Using probes
4. In the "Input source" settings, select the "Input connector": "RF Probe".
Probes are automatically detected when you plug them into the R&S FSV/A. The
detected information on the probe is displayed in the "Probes" tab of the "Input"
dialog box.
To determine whether the probe has been connected properly and recognized by the
R&S FSV/A, use the [SENSe:]PROBe<pb>:SETup:STATe? remote control command.
Impedance and attenuation
The measured signal from the probe is attenuated internally by the probe's specific
attenuation. For RF probes, the attenuation is compensated using a pre-defined "Probe
on RF Input" transducer factor. This special transducer factor is automatically activated
before the common RF data processing when you select "RF probe" as the input connector. The reference level is adjusted automatically.
A fixed impedance of 50 Ω is used for all probes to convert voltage values to power
levels.
4.2.1.1 Multimode function and offset compensation for modular RF probes
The R&S RT-ZM probe family features the MultiMode function which allows you to
switch between single-ended, differential, and common mode measurements without
reconnecting or resoldering the probe.
Four different input voltages can be measured with the MultiMode feature:
●
P-Mode: (pos.) Single-ended input voltage (Vp)
Voltage between the positive input terminal and ground
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●
N-Mode: (neg.) Single-ended input voltage (Vn)
Voltage between the negative input terminal and ground
●
DM-Mode: Differential mode input voltage (Vdm)
Voltage between the positive and negative input terminal
●
CM-Mode: Common mode input voltage (Vcm)
Mean voltage between the positive and negative input terminal vs. ground
The R&S FSV/A supports all probe modes. The mode is configured in the Chap-
ter 5.3.1.5, "Probe settings", on page 81.
Offset compensation
The R&S RT-ZM probes feature a comprehensive offset compensation function. The
compensation of DC components directly at the probe tip even in front of the active
probe amplifier is possible with an extremely wide compensation range of ±16 V (±24 V
for P and N modes).
Basics on I/Q data acquisition and processing
Using probes
The offset compensation feature is available for every MultiMode setting:
MultiMode
setting
DM-Mode Differential DC voltage ±16 V Probing single-ended signals, e.g. power
CM-Mode Common mode DC volt-
P-Mode DC voltage at positive
N-Mode DC voltage at negative
Offset compensation Offset compen-
sation range
±16 V Measurements of signals with high common
age
±24 V Measurement of single-ended AC signals
input terminal
±24 V Measurement of single ended AC signals
input terminal
Application
rails with high DC component and small AC
signal.
mode levels, e.g. current measurements
with a shunt resistor.
with high superimposed DC component at
the positive input terminal.
Note: The maximum voltage difference
between the positive and negative input terminals is 16 V.
with high superimposed DC component at
the negative input terminal.
Note: The maximum voltage difference
between the positive and negative input terminals is 16 V.
If the offset for DM-mode or CM-mode is changed, the offsets for the P-mode and Nmode are adapted accordingly, and vice versa.
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4.3 Basics on external mixers
Some background knowledge on basic terms and principles used with external mixers
is provided here for a better understanding of the required configuration settings.
● Frequency ranges................................................................................................... 28
● Two-port and three-port mixers...............................................................................29
● Bias current.............................................................................................................30
● Conversion loss tables............................................................................................30
● External mixers and large bandwidth extension options.........................................32
4.3.1 Frequency ranges
In a common spectrum analyzer, rather than providing one large (and thus inaccurate)
filter, or providing several filters to cover the required frequency range of the input signal (at a high cost), a single, very accurate filter is used. Therefore, the input signal
must be converted to the frequencies covered by the single accurate filter. This is done
by a mixer, which converts and multiplies the frequency of the input signal with the help
of the local oscillator (LO). The result is a higher and lower intermediate frequency (IF).
The local oscillator can be tuned within the supported frequency range of the input signal.
Basics on I/Q data acquisition and processing
Basics on external mixers
In order to extend the supported frequency range of the input signal, an external mixer
can be used. In this case, the LO frequency is output to the external mixer, where it is
mixed with the RF input from the original input signal. In addition, the harmonics of the
LO are mixed with the input signal, and converted to new intermediate frequencies.
Thus, a wider range of frequencies can be obtained. The IF from the external mixer is
then returned to the spectrum analyzer.
The frequency of the input signal can be expressed as a function of the LO frequency
and the selected harmonic of the first LO as follows:
fin = n * fLO + f
Where:
fin: Frequency of input signal
n: Order of harmonic used for conversion
fLO: Frequency of first LO: 8.05 GHz to 16.4 GHz
fIF: Intermediate frequency (variable; defined internally depending on RBW and span)
Thus, depending on the required frequency band, the appropriate order of harmonic
must be selected. For commonly required frequency ranges, predefined bands with the
appropriate harmonic order setting are provided. By default, the lowest harmonic order
is selected that allows conversion of input signals in the whole band.
IF
For the "USER" band, the order of harmonic is defined by the user. The order of harmonic can be between 3 and 128, the lowest usable frequency being 17.132 GHz.
The frequency ranges for pre-defined bands are described in Table 9-3.
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Changes to the band and mixer settings are maintained even after using the [PRESET]
function. A "Preset band" function allows you to restore the original band settings.
Extending predefined ranges
In some cases, the harmonics defined for a specific band allow for an even larger frequency range than the band requires. By default, the pre-defined range is used. However, you can take advantage of the extended frequency range by overriding the
defined start and stop frequencies by the maximum possible values ("RF Overrange"
option).
Additional ranges
If due to the LO frequency the conversion of the input signal is not possible using one
harmonic, the band must be split. An adjacent, partially overlapping frequency range
can be defined using different harmonics. In this case, the sweep begins using the harmonic defined for the first range, and at a specified frequency in the overlapping range
("handover frequency"), switches to the harmonic for the second range.
Basics on I/Q data acquisition and processing
Basics on external mixers
4.3.2 Two-port and three-port mixers
External mixers are connected to the R&S FSV/A at the LO OUT/IF IN and IF IN connectors.
When using three-port mixers, the LO signal output from the R&S FSV/A and the IF
input from the mixer are transmitted on separate connectors, whereas for two-port mixers, both signals are exchanged via the same connector (LO OUT/IF IN). Because of
the diplexer contained in the R&S FSV/A, the IF signal can be tapped from the line
which is used to feed the LO signal to the mixer.
Two-port mixer Three-port mixer
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In both cases, the nominal LO level is 15.5 dBm.
4.3.3 Bias current
Single-diode mixers generally require a DC voltage which is applied via the LO line.
This DC voltage is to be tuned to the minimum conversion loss versus frequency. Such
a DC voltage can be set via the "BIAS" function using the D/A converter of the
R&S FSV/A. The value to be entered is not the voltage but the short-circuit current.
The current is defined in the "Bias Settings" or set to the value of the conversion loss
table.
See "Bias Value" on page 68 and "Bias" on page 72.
Basics on I/Q data acquisition and processing
Basics on external mixers
The voltage U0 at the output of the operational amplifier can be set in the range –3.3 V
to +3.3 V. An open-circuit voltage U
the output of the voltage divider. A short-circuit current of I
+12 mA is obtained for a short circuit at the output of the voltage divider. In order to use
biasing it is not important to know the exact current flowing through the diode since the
conversion loss must be set to a minimum with the frequency. Therefore, it makes no
difference whether the setting is performed by an open-circuit voltage or by a short-circuit current. A DC return path is ensured via the 75 Ω resistor, which is an advantage
in some mixers.
4.3.4 Conversion loss tables
Conversion loss tables consist of value pairs that describe the correction values for
conversion loss at certain frequencies. Correction values for frequencies between the
reference values are obtained by interpolation. Linear interpolation is performed if the
table contains only two values. If it contains more than two reference values, spline
interpolation is carried out. Outside the frequency range covered by the table the conversion loss is assumed to be the same as that for the first and last reference value
(see Figure 4-4).
of –0.75 V to +0.75 V is obtained accordingly at
bias
= U0 / 260 Ω = -12 mA to
short
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Figure 4-4: Conversion loss outside the band's frequency range
Basics on I/Q data acquisition and processing
Basics on external mixers
Predefined conversion loss tables are often provided with the external mixer and can
be imported to the R&S FSV/A.
Alternatively, you can define your own conversion loss tables. Conversion loss tables
are configured and managed in the "Conversion loss Table Settings" tab of the "External Mixer Configuration" dialog box.
When using external mixers with optional bandwidth extensions larger than 400 MHz,
special conversion loss tables are required, see Chapter 4.3.5, "External mixers and
large bandwidth extension options", on page 32.
Importing CVL tables
The conversion loss table to be used for a particular measurement range is also
defined in the "External Mixer Configuration" dialog box.
The frequency range that the cvl table must cover depends on the used IF, which varies depending on the instrument and installed bandwidth extension options. Thus,
external mixers from Rohde & Schwarz provide multiple conversion loss table files.
When you select a storage path containing cvl files, or a particular cvl file from a
Rohde & Schwarz mixer for import, all available files are copied to the
C:\R_S\INSTR\USER\cvl\ directory on the R&S FSV/A. Provided .acl files are
renamed according to the following syntax:
<serial_number>_<harmonic_order>_<IF>.acl,
e.g. 12345_2_1330M.acl
To select a conversion loss table for use in a measurement, you merely have to select
the serial number for the external mixer in use. The R&S FSV/A automatically selects
the correct cvl file for the current IF. As an alternative, you can also select a userdefined conversion loss table (.acl file).
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Before copying any files to the C:\R_S\INSTR\USER\cvl\ directory, the R&S FSV/A
firmware moves any existing user-defined cvl tables to a backup subdirectory. To use
a user-defined cvl table later, select the file in the
C:\R_S\INSTR\USER\cvl\backup directory.
A validation check is then performed on the selected table to ensure that it complies
with the settings. In particular, the following is checked:
●
The assigned band name
●
The harmonic order
●
The mixer type
●
The table must contain at least one frequency that lies within the frequency range
for the band
Reference level
The maximum possible reference level depends on the maximum used conversion loss
value. Thus, the reference level can be adjusted for each range according to the used
conversion loss table or average conversion loss value. If a conversion loss value is
used which exceeds the maximum reference level, the reference level is adjusted to
the maximum value permitted by the firmware.
Basics on I/Q data acquisition and processing
Basics on external mixers
4.3.5 External mixers and large bandwidth extension options
If the bandwidth extension options R&S FSV3-B600/-B1000 are active, external mixers
with a bandwidth up to 1 GHz are supported. For information on which mixers are supported for these bandwidth options, see the R&S FSV/A data sheet. Two-port mixers
are not supported.
Depending on the installed and active bandwidth extension options, the used measurement bandwidth and IF, special conversion loss tables are required.
BW extension
option
any ≤40 MHz 732 MHz
B200/B400 40 MHz to 400 MHz 768 MHz
B600/B1000 >400 MHz 1536 MHz *.b5g, if available, otherwise *.b2g
While the common .acl files can be used, data acquisition with larger bandwidths
using such conversion loss tables leads to substantial inaccuracy. Using an average
conversion loss for the entire range (instead of a conversion loss table) during data
acquisition with the large bandwidth extension options causes even more inaccuracy.
In both cases, the UNCAL status message indicates that the measurement can have
inaccurate results.
Used meas bandwidth IF Required conversion loss table format
*.ACL
*.ACL
Special conversion loss tables (in *.b5g or *.b2g files) cannot be edited within the
R&S FSV/A firmware; they can only be imported and deleted.
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B600/B1000-specific conversion loss tables
A B600/B1000 conversion loss table consists of 43 magnitude correction values (as
opposed to 1 for .acl files). To each side of the specific frequency, 21 reference values are defined with an offset of 25 MHz to 1025 MHz. Thus, correction levels are
measured with a spacing of 50 MHz.
Example:
For example, for the level measured at the frequency 50 GHz, 43 correction levels are
defined:
●
21 for the frequencies 48.075 GHz, 49.125 GHz, 49.175 GHz, ..., 49.975 GHz
●
1 for the frequency 50 GHz
●
21 for the frequencies 50.025 GHz, 50.075 GHz, 50.125 GHz, ..., 51.025 GHz
B600/B1000-specific conversion loss tables are provided in files according to the following syntax:
<serial_no.>_MAG_<harmonic>_B2000.b2g
Basics on I/Q data acquisition and processing
Basics on external generator control
If the IF on the instrument differs to the IF of the correction data (specified in the conversion loss table file), the instrument automatically converts the correction data
accordingly.
Phase correction tables
In addition to the magnitude correction tables, B600/B1000 phase correction tables
with the same layout are defined in a separate file. Both files are always delivered as a
pair by the manufacturer of the external mixer. Currently, the R&S FSV/A uses only the
magnitude correction files for external mixers; the phase is assumed to be ideal (correction values are all 0).
B600/B1000-specific phase conversion loss tables are provided in files according to
the following syntax:
<serial_no.>_PHASE_<harmonic>_B2000.b2g
4.4 Basics on external generator control
Some background knowledge on basic terms and principles used for external generator control is provided here for a better understanding of the required configuration settings.
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External generator control is only available in the following applications.
●
Spectrum Analyzer
●
I/Q Analyzer
●
Analog Demodulation
●
Noise Figure Measurements
● External generator connections.............................................................................. 34
● Overview of supported generators..........................................................................36
● Generator setup files...............................................................................................37
● Calibration mechanism............................................................................................37
● Normalization.......................................................................................................... 38
● Reference trace, reference line and reference level............................................... 39
● Coupling the frequencies........................................................................................ 40
● Displayed information and errors............................................................................ 42
4.4.1 External generator connections
Basics on I/Q data acquisition and processing
Basics on external generator control
The external generator is controlled via a LAN connection.
For more information on configuring interfaces, see the "Remote Control Interfaces and
Protocols" section in the R&S FSV/A User Manual.
TTL synchronization
Some Rohde & Schwarz generators can be synchronized via TTL. The TTL interface is
included in the AUX Control connector of the External Generator Control option. Using
the TTL interface allows for considerably higher measurement rates, because the frequency stepping of the R&S FSV/A is directly coupled with the frequency stepping of
the generator. For details see Chapter 4.4.7, "Coupling the frequencies", on page 40.
In Figure 4-5 the TTL connection is illustrated using an R&S SMU generator, for example.
R&S SMU rear
Analyzer rear
BNC Blank
BNC Trigger
Figure 4-5: TTL connection for an R&S SMU generator
In Figure 4-6, the connection for an R&S SMW is shown.
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Basics on I/Q data acquisition and processing
Basics on external generator control
Signal generator
rear panel
BNC Trigger
BNC Blank
Figure 4-6: TTL connection for an R&S SMW generator
Signal generator
rear panel
BNC Trigger
Signal analyzer
rear panel
Signal analyzer
rear panel
BNC Blank
Figure 4-7: TTL connection for an R&S SMA100B generator
The external generator can be used to calibrate the data source by performing either
transmission or reflection measurements.
Transmission Measurement
This measurement yields the transmission characteristics of a two-port network. The
external generator is used as a signal source. It is connected to the input connector of
the DUT. The input of the R&S FSV/A is fed from the output of the DUT. A calibration
can be carried out to compensate for the effects of the test setup (e.g. frequency
response of connecting cables).
Figure 4-8: Test setup for transmission measurement
Reflection Measurement
Scalar reflection measurements can be carried out using a reflection-coefficient measurement bridge.
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Figure 4-9: Test setup for reflection measurement
Generated signal input
To use the functions of the external generator, an appropriate generator must be connected and configured correctly. In particular, the generator output must be connected
to the RF input of the R&S FSV/A.
External reference frequency
Basics on I/Q data acquisition and processing
Basics on external generator control
To enhance measurement accuracy, use a common reference frequency for both the
R&S FSV/A and the generator. If no independent 10 MHz reference frequency is available, connect the reference output of the generator with the reference input of the
R&S FSV/A. Enable usage of the external reference on the R&S FSV/A via "SETUP" >
"Reference" > "External Reference".
For more information on external references, see the "Instrument Setup" section in the
R&S FSV/A User Manual.
Connection errors
If no external generator is connected, if the connection address is not correct, or the
generator is not ready for operation, an error message is displayed (e.g."Ext. Generator TCPIP Handshake Error!", see Chapter 4.4.8, "Displayed information and errors",
on page 42).
4.4.2 Overview of supported generators
Generator type Generator type Generator type Generator type
SGS100A12 SMB100A1 SMCV100B3 SMU02
SGS100A6 SMB100A12 SMCV100B6 SMU02B31
SGT100A3 SMB100A2 SMCV100B7 SMU03
SGT100A6 SMB100A20 SMF100A SMU03B31
SMA01A SMB100A3 SMF22 SMU04
SMA100A3 SMB100A40 SMF22B2 SMU04B31
SMA100A6 SMB100A6 SMF43 SMU06
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Basics on I/Q data acquisition and processing
Basics on external generator control
Generator type Generator type Generator type Generator type
SMA100B3 SMB100B1 SMF43B2 SMU06B31
SMA100B6 SMB100B3 SMJ03 SMW03
SMA100B12 SMB100B6 SMJ06 SMW06
SMA100B20 SMBV100A3 SMM100A6 SMW07
SMA100B32 SMBV100A6 SMM100A7 SMW12
SMA100B40 SMBV100B3 SMM100A12 SMW20
SMA100B50 SMBV100B6 SMM100A20 SMW32
SMA100B67 SMC100A1 SMM100A31 SMW40
SMC100A3 SMM100A44 SMW44
4.4.3 Generator setup files
For each signal generator type to be controlled by the R&S FSV/A, configure a generator setup file and store it on the R&S FSV/A. The setup file defines the frequency and
power ranges supported by the generator, and information required for communication.
For the signal generators listed in Chapter 4.4.2, "Overview of supported generators",
on page 36, default setup files are provided. If necessary, you can edit or duplicate
these files for varying measurement setups or other instruments.
You can display the existing setup files in an editor in read-only mode directly from the
"External Generator" configuration dialog box. From there, you can edit them and store
them under a different name. Then they are available on the R&S FSV/A.
(For details see the R&S FSV/A User Manual).
4.4.4 Calibration mechanism
A common measurement setup includes a signal generator, a device under test (DUT),
and a signal and spectrum analyzer. Therefore, it is useful to measure the attenuation
or gain caused by the cables and connectors from the signal generator and the signal
analyzer in advance. The known level offsets can then be removed from the measurement results to obtain accurate information on the DUT.
Calculating the difference between the currently measured power and a reference
trace is referred to as calibration. Thus, the measurement results from the controlled
external generator - including the inherent distortions - can be used as a reference
trace to calibrate the measurement setup.
The inherent frequency and power level distortions can be determined by connecting
the R&S FSV/A to the signal generator. The R&S FSV/A sends a predefined list of frequencies to the signal generator (see also Chapter 4.4.7, "Coupling the frequencies",
on page 40). The signal generator then sends a signal with the specified level at each
frequency in the predefined list. The R&S FSV/A measures the signal and determines
the level offsets to the expected values.
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Saving calibration results
A reference dataset for the calibration results is stored internally as a table of value
pairs (frequency/level), one for each sweep point. The measured offsets can then be
used as calibration factors for subsequent measurement results. The calibration data
can also be stored permanently with the instrument settings using the "Save" function
in the toolbar.
The calibration can be performed using either transmission or reflection measurements. The selected type of measurement used to determine the reference trace is
included in the reference dataset.
4.4.5 Normalization
Once the measurement setup has been calibrated and the reference trace is available,
subsequent measurement results can be corrected according to the calibration factors,
if necessary. Results are corrected by subtracting the reference trace from the measurement results. This process is referred to as normalization and can be activated or
deactivated as required. If normalization is activated, "NOR" is displayed in the channel
bar, next to the indication that an external generator is being used ("Ext.Gen"). The
normalized trace from the calibration sweep is a constant 0 dB line, as <calibration
trace> - <reference trace> = 0.
Basics on I/Q data acquisition and processing
Basics on external generator control
As long as the same settings are used for measurement as for calibration, the normalized measurement results should not contain any inherent frequency or power distortions. Thus, the measured DUT values are very accurate.
Approximate normalization
As soon as any of the calibration measurement settings are changed, the stored reference trace is longer identical to the new measurement results. However, if the measurement settings do not deviate too much, the measurement results can still be normalized approximately using the stored reference trace. An "APX" label in the channel
bar (instead of "NOR") indicates the approximated normalization.
Approximation is necessary if one or more of the following values deviate from the calibration settings:
●
Coupling (RBW, VBW, SWT)
●
Reference level, RF attenuation
●
Start or stop frequency
●
Output level of external generator
●
Detector (max. peak, min. peak, sample, etc.)
●
Frequency deviation at a maximum of 1001 points within the set sweep limits (corresponds to a doubling of the span)
Differences in level settings between the reference trace and the current instrument
settings are considered automatically. If the span is reduced, a linear interpolation of
the intermediate values is applied. If the span increases, the values at the left or right
border of the reference dataset are extrapolated to the current start or stop frequency.
The reference dataset is extended by constant values.
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Thus, you can change various instrument settings without giving up normalization. The
necessity to carry out a new normalization is reduced to a minimum.
The normalized trace in the display
The normalized reference trace is also displayed in the spectrum diagram, by default at
the top of the diagram (= 100% of the window height). It is indicated by a red line
labeled "NOR", followed by the current reference value. However, it can be shifted vertically to reflect an attenuation or gain caused by the measured DUT (see also "Shifting
the reference line (and normalized trace)" on page 40).
Restoring the calibration settings
If the measurement settings no longer match the instrument settings with which the
calibration was performed (indicated by the "APX" or no label next to "Ext.TG" in the
channel bar), you can restore the calibration settings, which are stored with the reference dataset on the R&S FSV/A.
Storing the normalized reference trace as a transducer factor
Basics on I/Q data acquisition and processing
Basics on external generator control
The (inverse) normalized reference trace can also be stored as a transducer factor for
use in other R&S FSV/A applications that do not support external generator control.
The normalized trace data is converted to a transducer with unit dB and stored in a file
with the specified name and the suffix .trd under c:\r_s\instr\trd. The frequency points are allocated in equidistant steps between the start and stop frequency.
Transducer factors are useful, for example, to determine the effects of a particular
device component and then remove these effects from a subsequent measurement
which includes this component.
For an example, see the "External Generator Control: Measurement Examples" section
in the R&S FSV/A User Manual.
Note that the normalized measurement data is stored, not the original reference trace.
Thus, if you store the normalized trace directly after calibration, without changing any
settings, the transducer factor is 0 dB for the entire span (by definition of the normalized trace).
4.4.6 Reference trace, reference line and reference level
Reference trace
The calibration results are stored internally on the R&S FSV/A as a reference trace.
For each measured sweep point, the offset to the expected values is determined. If
normalization is activated, the offsets in the reference trace are removed from the current measurement results to compensate for the inherent distortions.
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OffsetAnalyzerGenerator
F
atorDeno
Numerator
FF
min
Reference line
The reference line is defined by the Reference Value and Reference Position in the
"External Generator" > "Source Calibration" settings. It is similar to the Reference
Level defined in the "Amplitude" settings. However, as opposed to the reference level,
this reference line only affects the y-axis scaling in the diagram. It has no effect on the
expected input power level or the hardware settings.
The reference line determines the range and the scaling of the y-axis, just as the reference level does.
The normalized reference trace (0 dB directly after calibration) is displayed on this reference line, indicated by a red line in the diagram. By default, the reference line is displayed at the top of the diagram. If you shift the reference line, the normalized trace is
shifted, as well.
Shifting the reference line (and normalized trace)
You can shift the reference line - and thus the normalized trace - in the result display by
changing the Reference Position or the Reference Value.
Basics on I/Q data acquisition and processing
Basics on external generator control
If the DUT inserts a gain or an attenuation in the measurement, this effect can be
reflected in the result display on the R&S FSV/A. To reflect a power offset in the measurement trace, change the Reference Value.
4.4.7 Coupling the frequencies
As described in Chapter 4.4.5, "Normalization", on page 38, normalized measurement
results are very accurate as long as the same settings are used as for calibration.
Although approximate normalization is possible, it is important to consider the required
frequencies for calibration in advance. The frequencies and levels supported by the
connected signal generator are provided for reference with the interface configuration.
Frequency coupling means that the generator frequency and the frequency of the
R&S FSV/A are the same.
●
Manual coupling: a single frequency is defined
●
Automatic coupling: a series of frequencies is defined (one for each sweep
point), based on the current frequency at the RF input of the R&S FSV/A. The RF
frequency range covers the currently defined span of the R&S FSV/A (unless limited by the range of the signal generator).
Automatic coupling
If automatic coupling is used, the output frequency of the generator (source frequency)
is calculated as follows:
Equation 4-1: Output frequency of the generator
Where:
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Basics on I/Q data acquisition and processing
Basics on external generator control
F
Generator
F
Analyzer
Numerator = multiplication factor for F
Denominator = division factor for F
F
Offset
= output frequency of the generator
= current frequency at the RF input of the R&S FSV/A
Analyzer
Analyzer
= frequency offset for F
, for example for frequency-converting measure-
Analyzer
ments or harmonics measurements
The value range for the offset depends on the selected generator. The default setting is
0 Hz. Offsets other than 0 Hz are indicated by the "FRQ" label in the channel bar (see
also Chapter 4.4.8, "Displayed information and errors", on page 42).
Swept frequency range
The F
values for the calibration sweep start with the start frequency and end with
Analyzer
the stop frequency defined in the "Frequency" settings of the R&S FSV/A. The resulting output frequencies (Result Frequency Start and Result Frequency Stop) are displayed in "External Generator" > "Measurement Configuration" for reference.
If the resulting frequency range exceeds the allowed ranges of the signal generator, an
error message is displayed (see Chapter 4.4.8, "Displayed information and errors",
on page 42). The Result Frequency Start and Result Frequency Stop values are corrected to comply with the range limits.
The calibration sweep nevertheless covers the entire span defined by the R&S FSV/A.
However, no input is received from the generator outside the generator's defined limits.
TTL synchronization
Some Rohde & Schwarz signal generators support TTL synchronization. The TTL
interface is included in the AUX control connector of the External Generator Control
option. Without TTL synchronization, the R&S FSV/A sets the generator frequency for
each frequency point individually, and only when the setting procedure is finished, the
R&S FSV/A can measure the next sweep point.
For generators with a TTL interface, the R&S FSV/A sends a list of the frequencies to
be set to the generator before the beginning of the first sweep. Then the R&S FSV/A
starts the sweep and the next frequency point is selected by both the R&S FSV/A and
the generator using the TTL handshake line "TRIGGER". The R&S FSV/A can only
measure a value when the generator signals the end of the setting procedure via the
"BLANK" signal.
Using the TTL interface allows for considerably higher measurement rates, because
the frequency stepping of the R&S FSV/A is directly coupled with the frequency stepping of the generator.
Reverse sweep
The frequency offset for automatic coupling can be used to sweep in the reverse direction. To do so, define a negative offset in the external generator measurement configu-
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ration. (Note that the frequency is defined as the unsigned value of the equation, thus a
negative frequency is not possible.)
Example: Example for reverse sweep
F
AnalyzerStart
F
AnalyzerStop
F
Offset
= 100 MHz
= 200 MHz
= -300 MHz
Numerator = Denominator = 1
→F
GeneratorStart
→F
GeneratorStop
If the offset is adjusted so that the sweep of the generator crosses the minimum generator frequency, a message is displayed in the status bar ("Reverse Sweep via min. Ext.
Generator Frequency!").
Example: Example for reverse sweep via minimum frequency
F
AnalyzerStart
F
AnalyzerStop
F
Offset
F
min
= 100 MHz
= 200 MHz
= -150 MHz
= 20 MHz
Numerator = Denominator = 1
→F
GeneratorStart
→F
GeneratorStop
= 200 MHz
= 100 MHz
= 50 MHz
= 50 MHz via F
Basics on I/Q data acquisition and processing
Basics on external generator control
min
4.4.8 Displayed information and errors
Channel bar
If external generator control is active, some additional information is displayed in the
channel bar.
Label Description
EXT TG: <source power> External generator active; signal sent with <source power> level
LVL Power Offset (see "Source Offset" on page 86
FRQ Frequency Offset (see "(Automatic) Source Frequency (Numerator/Denomi-
nator/Offset)" on page 87
NOR Normalization on;
No difference between reference setting and measurement
APX (approximation) Normalization on;
Deviation from the reference setting occurs
- Aborted normalization or no calibration performed yet
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Error and status messages
The following status and error messages can occur during external generator control.
Message Description
Basics on I/Q data acquisition and processing
Basics on input from I/Q data files
"Ext. Generator TCPIP Handshake Error!" /
"Ext. Generator TTL Handshake Error!"
"Ext. Generator Limits Exceeded!" The allowed frequency or power ranges for the generator
"Reverse Sweep via min. Ext. Generator Frequency!"
"Ext. Generator File Syntax Error!" Syntax error in the generator setup file (see Chap-
"Ext. Generator Command Error!" Missing or wrong command in the generator setup file
"Ext. Generator Visa Error!" Error with Visa driver provided with installation (very
Connection to the generator is not possible, e.g. due to a
cable damage or loose connection or wrong address.
were exceeded.
Reverse sweep is performed; frequencies are reduced to
the minimum frequency, then increased again; see
"Reverse sweep" on page 41.
ter 4.4.3, "Generator setup files", on page 37
(see Chapter 4.4.3, "Generator setup files", on page 37
unlikely)
Overloading
At a reference level of -10 dBm and at an external generator output level of the same
value, the R&S FSV/A operates without overrange reserve. That means the
R&S FSV/A is in danger of being overloaded if a signal is applied whose amplitude is
higher than the reference line. In this case, either the message "RF OVLD" for overload or "ADC OVLD" for exceeded display range (clipping of the trace at the upper diagram border = overrange) is displayed in the status line.
Overloading can be avoided as follows:
●
Reducing the output level of the external generator ("Source Power" on page 86
in "External Generator > Measurement Configuration")
●
Increasing the reference level (Reference Level in the "Amplitude" menu)
4.5 Basics on input from I/Q data files
The I/Q data to be evaluated in a particular R&S FSV/A application can not only be
captured by the application itself, it can also be loaded from a file, provided it has the
correct format. The file is then used as the input source for the application.
For example, you can capture I/Q data using the I/Q Analyzer application, store it to a
file, and then analyze the signal parameters for that data later using the Pulse application (if available).
The I/Q data file must be in one of the following supported formats:
.iq.tar
●
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.iqw
●
.csv
●
.mat
●
.wv
●
.aid
●
(For details, see Chapter C, "Reference: supported I/Q file formats", on page 372)
Only a single data stream can be used as input, even if multiple streams are stored in
the file.
An application note on converting Rohde & Schwarz I/Q data files is available from the
Rohde & Schwarz website:
1EF85: Converting R&S I/Q data files
For I/Q file input, the stored I/Q data remains available as input for any number of subsequent measurements. When the data is used as an input source, the data acquisition settings in the current application (attenuation, center frequency, measurement
bandwidth, sample rate) can be ignored. As a result, these settings cannot be changed
in the current application. Only the measurement time can be decreased, in order to
perform measurements on an extract of the available data (from the beginning of the
file) only.
Basics on I/Q data acquisition and processing
Basics on input from I/Q data files
For some file formats that do not provide the sample rate and measurement time or
record length, you must define these parameters manually. Otherwise the traces are
not visible in the result displays.
For details, see Table C-1.
When using input from an I/Q data file, the [RUN SINGLE] function starts a single measurement (i.e. analysis) of the stored I/Q data, while the [RUN CONT] function repeatedly analyzes the same data from the file.
Sample iq.tar files
If you have the optional R&S FSV/A VSA application (R&S FSV3-K70), some sample
iq.tar files are provided in the C:/R_S/Instr/user/vsa/DemoSignals directory
on the R&S FSV/A.
Furthermore, you can create your own iq.tar files in the I/Q Analyzer, see Chap-
ter 8.2, "How to export and import I/Q data", on page 166.
Pre-trigger and post-trigger samples
In applications that use pre-triggers or post-triggers, if no pre-trigger or post-trigger
samples are specified in the I/Q data file, or too few trigger samples are provided to
satisfy the requirements of the application, the missing pre- or post-trigger values are
filled up with zeros. Superfluous samples in the file are dropped, if necessary. For pre-
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trigger samples, values are filled up or omitted at the beginning of the capture buffer,
for post-trigger samples, values are filled up or omitted at the end of the capture buffer.
4.6 IF and video signal output
The measured IF signal or displayed video signal (i.e. the filtered and detected IF signal) can be provided at the IF output connector of the R&S FSV/A.
The IF output is a signal of the measured level at a specified frequency.
Restrictions
Note the following restrictions for data output:
●
IF and video output is only available in the time domain (zero span).
●
For I/Q data, only IF output is available.
●
IF output is not available if any of the following conditions apply:
– The sample rate is larger than 200 MHz (upsampling)
Basics on I/Q data acquisition and processing
Receiving and providing trigger signals
4.7 Receiving and providing trigger signals
Using one of the "Trigger Input / Output" connectors of the R&S FSV/A, the
R&S FSV/A can use a signal from an external device as a trigger to capture data.
Alternatively, the internal trigger signal used by the R&S FSV/A can be output for use
by other connected devices. Using the same trigger on several devices is useful to
synchronize the transmitted and received signals within a measurement.
For details on the connectors see the R&S FSV/A "Getting Started" manual.
External trigger as input
If the trigger signal for the R&S FSV/A is provided by an external device, the trigger
signal source must be connected to the R&S FSV/A and the trigger source must be
defined as "External" in the R&S FSV/A.
Trigger output
The R&S FSV/A can provide output to another device either to pass on the internal
trigger signal, or to indicate that the R&S FSV/A itself is ready to trigger.
The trigger signal can be output by the R&S FSV/A automatically, or manually by the
user. If it is provided automatically, a high signal is output when the R&S FSV/A has
triggered due to a sweep start ("Device Triggered"), or when the R&S FSV/A is ready
to receive a trigger signal after a sweep start ("Trigger Armed").
Manual triggering
If the trigger output signal is initiated manually, the length and level (high/low) of the
trigger pulse is also user-definable. Note, however, that the trigger pulse level is always
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opposite to the constant signal level defined by the output "Level" setting, e.g. for
"Level" = "High", a constant high signal is output to the connector until the "Send Trigger" button is selected. Then, a low pulse is provided.
Basics on I/Q data acquisition and processing
Basics on FFT
4.8
Basics on FFT
The I/Q Analyzer measures the power of the signal input over time. To convert the time
domain signal to a frequency spectrum, an FFT (Fast Fourier Transformation) is performed which converts a vector of input values into a discrete spectrum of frequencies.
4.8.1 Window functions
t[s]
FFT
f[Hz]
The Fourier transformation is not performed on the entire captured data in one step.
Only a limited number of samples is used to calculate an individual result. This process
is called windowing.
After sampling in the time domain, each window is multiplied with a specific window
function. Windowing helps minimize the discontinuities at the end of the measured signal interval and thus reduces the effect of spectral leakage, increasing the frequency
resolution.
Various different window functions are provided in the R&S FSV/A to suit different input
signals. Each of the window functions has specific characteristics, including some
advantages and some trade-offs. Consider these characteristics to find the optimum
solution for the measurement task.
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Ignoring the window function - rectangular window
The rectangular window function is in effect not a function at all, it maintains the original sampled data. This may be useful to minimize the required bandwidth. However, be
aware that if the window does not contain exactly one period of your signal, heavy
sidelobes may occur, which do not exist in the original signal.
Table 4-3: Characteristics of typical FFT window functions
Basics on I/Q data acquisition and processing
Basics on FFT
Window type Frequency
Rectangular Best Worst Worst No function applied.
Blackman-Harris
(default)
Gauss (Alpha
= 0.4)
Flattop Worst Best Good Accurate single tone measurements
5-Term Good Good Best Measurements with very high
4.8.2 Overlapping
The I/Q Analyzer calculates multiple FFTs per measurement by dividing one captured
record into several windows. Furthermore, the I/Q Analyzer allows consecutive windows to overlap. Overlapping "reuses" samples that were already used to calculate the
preceding FFT result.
Magnitude
resolution
Good Good Good Harmonic detection and spurious
Good Good Good Weak signals and short duration
resolution
Sidelobe suppression
Measurement recommendation
Separation of two tones with almost
equal amplitudes and a small frequency distance
emission detection
dynamic range
In advanced FFT mode with averaging, the overlapping factor can be set freely. The
higher the overlap factor, the more windows are used. This leads to more individual
results and improves detection of transient signal effects. However, it also extends the
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duration of the calculation. The size of the window can be defined manually according
to the record length, the overlap factor, and the FFT length.
An FFT overlap of 67%, for example, means the second FFT calculation uses the last
67% of the data of the first FFT. It uses only 33% new data. The third FFT still covers
33% of the first FFT and 67% of the second FFT, and so on.
Figure 4-10: Overlapping FFTs
In "Manual" or "Auto" FFT mode, an FFT length of 4096 and a window length of 4096
(or the record length, if shorter) is used to calculate the spectrum.
Basics on I/Q data acquisition and processing
Basics on FFT
Combining results - trace detector
If the record length permits, multiple overlapping windows are calculated and combined
to create the final spectrum using the selected trace detector. If necessary, the trace
detector is also used to reduce the number of calculated frequency points (defined by
the FFT length) to the defined number of sweep points. By default, the Autopeak trace
detector is used.
Since the frequency points are reduced to the number of sweep points, using a detector other than "Auto Peak" and fewer than 4096 sweep points can lead to false level
results.
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4.8.3 Dependencies between FFT parameters
FFT analysis in the R&S FSV/A is highly configurable. Several parameters, including
the resolution bandwidth, record length, and FFT length, are user-definable. Note,
however, that several parameters are correlated and not all can be configured independently of the others.
Record Length
Defines the number of I/Q samples to capture. By default, the number of sweep points
is used. The record length is calculated as the measurement time multiplied by the
sample rate.
If you change the record length, the Meas Time is automatically changed, as well.
For FFTs using only a single window ("Single" mode), the record length (which is then
identical to the FFT length) must not exceed 512k.
FFT Length
Defines the number of frequency points determined by each FFT calculation. The more
points are used, the higher the resolution in the spectrum becomes, but the longer the
calculation takes.
Basics on I/Q data acquisition and processing
Basics on FFT
In "Auto" or "Manual" mode, an FFT length of 4096 is used.
In advanced FFT mode, the FFT length is user-definable. If you use the arrow keys or
the rotary knob to change the FFT length, the value is incremented or decremented by
powers of 2. If you enter the value manually, any integer value from 3 to 524288 is
available.
If the FFT length is longer than the Window Length the sample data is filled up with
zeros up to the FFT length. The FFT is then performed using interpolated frequency
points.
For an FFT length that is not a power of 2, a DFT (discrete Fourier transform) is performed, which requires more time for calculation, but avoids the effects of interpolation.
To display all calculated frequency points (defined by the FFT length), the number of
sweep points is set to the FFT length automatically in advanced FFT mode.
Window Length
Defines the number of samples to be included in a single window in averaging mode.
(In single mode, the window length corresponds to the "Record Length" on page 109.)
Values from 3 to 4096 are available in "Manual" mode; in "Advanced" FFT mode, values from 3 to 524288 are available. However, the window length must not be longer
than the FFT Length.
If the window length is shorter than the FFT Length, the sample data is filled up with
zeros up to the FFT length.
If the window length is longer than the Record Length (that is, not enough samples are
available), a window length the size of the Record Length is used for calculation.
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LengthWindow
RateSample
BandwidthNormalizedRBW
3
RateSample*BandwidthNormalized
RBW
max
LengthcordRe,4096min
RateSampleBandwidth*Normalized
RBW
min
The window length and the Window Overlap determine how many FFT calculations
must be performed for each record in averaging mode (see "Transformation Algorithm"
on page 110).
4.8.4 Frequency resolution of FFT results - RBW
The resolution bandwidth defines the minimum frequency separation at which the
individual components of a spectrum can be distinguished. Small values result in high
precision, as the distance between two distinguishable frequencies is small. Higher values decrease the precision, but increase measurement speed.
The RBW is determined by the following equation:
Equation 4-2: Definition of RBW
(Note: The normalized bandwidth is a fixed value that takes the noise bandwidth of the
window function into consideration.)
Basics on I/Q data acquisition and processing
Basics on FFT
The maximum RBW is restricted by the Analysis Bandwidth, or by the following equation, whichever is higher:
If a higher spectral resolution is required, the number of samples must be increased by
using a higher sample rate or longer record length.
The minimum achievable RBW depends on the sample rate and record length, according to the following equation:
To simplify operation, some parameters are coupled and automatically calculated, such
as record length and RBW.
RBW mode
Depending on the selected RBW mode, the resolution bandwidth is either determined
automatically or can be defined manually.
Auto mode:
This is the default mode in the I/Q Analyzer. The RBW is determined automatically
depending on the Sample Rate and Window Length, where the window length corresponds to the Record Length, or a maximum of 4096.
If the record length is larger than the window length, multiple windows are combined;
the FFT length is 4096.
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A Flatop window function is used.
Manual mode:
The RBW is user-definable.
The Window Length is adapted to comply with Equation 4-2. Since only window
lengths with integer values can be employed, the Sample Rate is adapted, if necessary, to obtain an integer window length value.
If the record length is larger than the window length, multiple windows are combined;
the FFT length is 4096.
A Flatop window function is used.
Advanced FFT mode
The RBW is determined by the advanced FFT parameters, depending on the selected
FFT calculation methods method.
4.8.5 FFT calculation methods
Basics on I/Q data acquisition and processing
Basics on FFT
FFT calculation can be performed using different methods.
Single
In single mode, one FFT is calculated for the entire record length, that means the window length is identical to the record length.
If the defined FFT Length is larger than the record length, zeros are appended to the
captured data to reach the FFT length.
Figure 4-11: FFT parameters for single FFT calculation
Averaging
In averaging mode, several overlapping FFTs are calculated for each record; the
results are combined to determine the final FFT result for the record.
The number of FFTs to be combined is determined by the Window Overlap and the
Window Length.
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Figure 4-12: FFT parameters for averaged FFT calculation
Basics on I/Q data acquisition and processing
Basics on FFT
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5 Configuration
Access: [MODE] > "I/Q Analyzer"
The I/Q Analyzer is a special application on the R&S FSV/A.
When you switch to an I/Q Analyzer channel the first time, a set of parameters is
passed on from the currently active application. After initial setup, the parameters for
the channel are stored upon exiting and restored upon re-entering the channel. Thus,
you can switch between applications quickly and easily.
When you activate a channel for the I/Q Analyzer application, data acquisition from the
input signal is started automatically with the default configuration. The "I/Q Analyzer"
menu is displayed and provides access to the most important configuration functions.
The remote commands required to perform these tasks are described in Chapter 9,
"Remote commands to perform measurements with I/Q data", on page 169.
Importing and Exporting I/Q Data
The I/Q data to be evaluated in the I/Q Analyzer application can not only be captured
by the I/Q Analyzer itself, it can also be imported to the R&S FSV/A, provided it has the
correct format. Furthermore, the captured I/Q data from the I/Q Analyzer can be exported for further analysis in external applications.
For details see Chapter 7, "I/Q data import and export", on page 161.
Configuration
Configuration overview
● Configuration overview............................................................................................53
● Import/export functions............................................................................................55
● Data input and output settings................................................................................ 59
● Amplitude................................................................................................................ 92
● Frequency settings..................................................................................................98
● Trigger settings....................................................................................................... 99
● Data acquisition and bandwidth settings...............................................................106
● Display configuration.............................................................................................114
● Adjusting settings automatically............................................................................ 114
5.1 Configuration overview
Access: all menus
Throughout the channel configuration, an overview of the most important currently
defined settings is provided in the "Overview".
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Multiple access paths to functionality
The easiest way to configure a channel is via the "Overview" dialog box, which is available from all menus.
Alternatively, you can access the individual dialog boxes from the corresponding menu
items, or via tools in the toolbars, if available.
In this documentation, only the most convenient method of accessing the dialog boxes
is indicated - usually via the "Overview".
Configuration
Configuration overview
Figure 5-1: Configuration Overview for I/Q Analyzer primary
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 channel from input over
processing to output and analysis by stepping through the dialog boxes as indicated in
the "Overview".
The "Overview" for the I/Q Analyzer provides quick access to the following configuration dialog boxes (listed in the recommended order of processing):
1. Input settings
See Chapter 5.3.1, "Input source settings", on page 59
2. Amplitude settings
See Chapter 5.4, "Amplitude", on page 92
3. Frequency settings
See Chapter 5.5, "Frequency settings", on page 98
4. Optionally, Trigger/Gate settings
See Chapter 5.6, "Trigger settings", on page 99
5. Bandwidth settings
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See Chapter 5.7, "Data acquisition and bandwidth settings", on page 106
6. Optionally, output settings
See Chapter 5.3.2, "Output settings", on page 91
7. Analysis settings and functions
See Chapter 6, "Analysis", on page 119
8. Display configuration
See Chapter 5.8, "Display configuration", on page 114
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 channel tab) to change a specific setting.
For step-by-step instructions on configuring I/Q Analyzer measurements, see Chap-
ter 8.1, "How to perform measurements in the I/Q Analyzer application", on page 166.
Configuration
Import/export functions
Preset Channel
Select the "Preset Channel" button in the lower left-hand corner of the "Overview" to
restore all measurement settings in the current channel 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 channels on the
R&S FSV/A (except for the default channel)!
Remote command:
SYSTem:PRESet:CHANnel[:EXEC] on page 179
Specific Settings for
The channel 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.
5.2 Import/export functions
Access: "Save"/ "Open" icon in the toolbar > "Import" / "Export"
Access (Import I/Q data): [Input Output] > "Input Source Config" > "I/Q File"
The R&S FSV/A provides various evaluation methods for the results of the performed
measurements. However, you may want to evaluate the data with further, external
applications. In this case, you can export the measurement data to a standard format
file (ASCII or XML). Some of the data stored in these formats can also be re-imported
to the R&S FSV/A for further evaluation later, for example in other applications.
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The following data types can be exported (depending on the application):
●
Trace data
●
Table results, such as result summaries, marker peak lists etc.
●
I/Q data
I/Q data can only be imported and exported in applications that process I/Q data, such
as the I/Q Analyzer or optional applications.
See the corresponding user manuals for those applications for details.
Exporting I/Q data is only possible in single sweep mode (Continuous Sweep / Run
Cont).
Importing I/Q data is also possible in continuous sweep mode.
For more information about importing I/Q data files, see Chapter 5.3.1.2, "Settings for
input from I/Q data files", on page 62.
Import............................................................................................................................56
Export............................................................................................................................56
└ Export Trace to ASCII File.............................................................................. 56
└ Trace Export Configuration.............................................................................58
└ I/Q Export........................................................................................................58
Configuration
Import/export functions
└ File Type...............................................................................................57
└ Decimal Separator................................................................................58
└ Column Separator.................................................................................58
└ File Explorer..........................................................................................58
└ File Explorer..........................................................................................59
Import
Access: "Save/Recall" > Import
Provides functions to import data.
For more information about importing I/Q data files, see Chapter 5.3.1.2, "Settings for
input from I/Q data files", on page 62.
Export
Access: "Save/Recall" > Export
Opens a submenu to configure data export.
Export Trace to ASCII File ← Export
Saves the selected trace or all traces in the currently active result display to the specified file and directory in the selected ASCII format.
"File Explorer": Instead of using the file manager of the R&S FSV/A firmware, you can
also use the Microsoft Windows File Explorer to manage files.
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Configuration
Import/export functions
Note: Secure user mode.
In secure user mode, settings that are stored on the instrument are stored to volatile
memory, which is restricted to 256 MB. Thus, a "memory limit reached" error can occur
although the hard disk indicates that storage space is still available.
To store data permanently, select an external storage location such as a USB memory
device.
For details, see "Protecting Data Using the Secure User Mode" in the "Data Management" section of the R&S FSV3000/ FSVA3000 base unit user manual.
Remote command:
MMEMory:STORe<n>:TRACe on page 360
File Type ← Export Trace to ASCII File ← Export
Determines the format of the ASCII file to be imported or exported.
Depending on the external program in which the data file was created or is evaluated,
a comma-separated list (CSV) or a plain data format (DAT) file is required.
Remote command:
FORMat:DEXPort:FORMat on page 358
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Decimal Separator ← Export Trace to ASCII File ← 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 358
Column Separator ← Export Trace to ASCII File ← Export
Selects the character that separates columns in the exported ASCII file. The character
can be either a semicolon, a comma or a tabulator (tab).
Example for semicolon:
Type;FSV3007;Version;1.80;Date;01.Jan 3000;
Example for comma:
Type,FSV3007,
Version,1.80,
Date,01.Jan 3000,
Example for tabulator (tab after the last column is not visible):
Type FSV3007
Version 1.80
Date 01.Jan 3000
Configuration
Import/export functions
The selected column separator setting remains the same, even after a preset.
Remote command:
FORMat:DEXPort:CSEParator on page 357
File Explorer ← Export Trace to ASCII File ← Export
Opens the Microsoft Windows File Explorer.
Remote command:
not supported
Trace Export Configuration ← Export
Opens the "Traces" dialog box to configure the trace and data export settings.
I/Q Export ← Export
Opens a file selection dialog box to define an export file name to which the I/Q data is
stored. This function is only available in single sweep mode.
It is not available in the Spectrum application, only in applications that process I/Q
data, such as the I/Q Analyzer or optional applications.
For details, see the description in the R&S FSV/A I/Q Analyzer User Manual ("Importing and Exporting I/Q Data").
Note: Storing large amounts of I/Q data (several Gigabytes) can exceed the available
(internal) storage space on the R&S FSV/A. In this case, it can be necessary to use an
external storage medium.
Note: Secure user mode.
In secure user mode, settings that are stored on the instrument are stored to volatile
memory, which is restricted to 256 MB. Thus, a "memory limit reached" error can occur
although the hard disk indicates that storage space is still available.
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To store data permanently, select an external storage location such as a USB memory
device.
For details, see "Protecting Data Using the Secure User Mode" in the "Data Management" section of the R&S FSV3000/ FSVA3000 base unit user manual.
Remote command:
MMEMory:STORe<n>:IQ:STATe on page 363
MMEMory:STORe<n>:IQ:COMMent on page 362
File Explorer ← I/Q Export ← Export
Opens the Microsoft Windows File Explorer.
Remote command:
not supported
5.3 Data input and output settings
Access: "Overview" > "Input"/ "Output"
Configuration
Data input and output settings
The R&S FSV/A can analyze signals from different input sources and provide various
types of output (such as noise source control or trigger signals).
For background information on providing input and output or working with power sensors, see the R&S FSV/A User Manual.
● Input source settings...............................................................................................59
● Output settings........................................................................................................91
5.3.1 Input source settings
Access: "Overview" > "Input/Frontend" > "Input Source"
The input source determines which data the R&S FSV/A analyzes.
The default input source for the R&S FSV/A is "Radio Frequency", i.e. the signal at the
"RF Input" connector of the R&S FSV/A. If no additional options are installed, this is the
only available input source.
● Radio frequency input............................................................................................. 59
● Settings for input from I/Q data files........................................................................62
● External mixer settings............................................................................................63
● External frontend settings....................................................................................... 74
● Probe settings......................................................................................................... 81
● External generator control settings......................................................................... 83
5.3.1.1 Radio frequency input
Access: "Overview" > "Input/Frontend" > "Input Source" > "Radio Frequency"
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RF Input Protection
The RF input connector of the R&S FSV/A must be protected against signal levels that
exceed the ranges specified in the data sheet. Therefore, the R&S FSV/A is equipped
with an overload protection mechanism for DC and signal frequencies up to 30 MHz.
This mechanism becomes active as soon as the power at the input mixer exceeds the
specified limit. It ensures that the connection between RF input and input mixer is cut
off.
When the overload protection is activated, an error message is displayed in the status
bar ("INPUT OVLD"), and a message box informs you that the RF input was disconnected. Furthermore, a status bit (bit 3) in the STAT:QUES:POW status register is set.
In this case, you must decrease the level at the RF input connector and then close the
message box. Then measurement is possible again. Reactivating the RF input is also
possible via the remote command INPut<ip>:ATTenuation:PROTection:RESet.
Configuration
Data input and output settings
Radio Frequency State................................................................................................. 60
Input Coupling...............................................................................................................60
Impedance.................................................................................................................... 61
Direct Path.................................................................................................................... 61
YIG-Preselector.............................................................................................................62
Input Connector.............................................................................................................62
Radio Frequency State
Activates input from the "RF Input" connector.
Remote command:
INPut<ip>:SELect on page 183
Input Coupling
The RF input of the R&S FSV/A can be coupled by alternating current (AC) or direct
current (DC).
For an active external frontend, input coupling is always DC.
AC coupling blocks any DC voltage from the input signal. AC coupling is activated by
default to prevent damage to the instrument. Very low frequencies in the input signal
can be distorted.
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However, some specifications require DC coupling. In this case, you must protect the
instrument from damaging DC input voltages manually. For details, refer to the data
sheet.
Remote command:
INPut<ip>:COUPling on page 181
Impedance
The R&S FSV/A has an internal impedance of 50 Ω. However, some applications use
other impedance values. To match the impedance of an external application to the
impedance of the R&S FSV/A, an impedance matching pad can be inserted at the
input. If the type and impedance value of the used matching pad is known to the
R&S FSV/A, it can convert the measured units accordingly so that the results are calculated correctly.
For an active external frontend, impedance is always 50 Ω.
The impedance conversion does not affect the level of the output signals (such as IF,
video, demod).
"50Ω"
Configuration
Data input and output settings
(Default:) no conversion takes place
"75Ω"
"User"
Remote command:
INPut<ip>:IMPedance on page 183
INPut<ip>:IMPedance:PTYPe on page 183
Direct Path
Enables or disables the use of the direct path for small frequencies.
In spectrum analyzers, passive analog mixers are used for the first conversion of the
input signal. In such mixers, the LO signal is coupled into the IF path due to its limited
isolation. The coupled LO signal becomes visible at the RF frequency 0 Hz. This effect
is referred to as LO feedthrough.
To avoid the LO feedthrough the spectrum analyzer provides an alternative signal path
to the A/D converter, referred to as the direct path. By default, the direct path is
selected automatically for RF frequencies close to zero. However, this behavior can be
disabled. If "Direct Path" is set to "Off", the spectrum analyzer always uses the analog
mixer path.
For an active external frontend, the direct path is always used automatically for frequencies close to zero.
"Auto"
"Off"
Remote command:
INPut<ip>:DPATh on page 182
The 50 Ω input impedance is transformed to a higher impedance
using a 75 Ω adapter of the selected "Pad Type": "Series-R" (default)
or "MLP" (Minimum Loss Pad)
The 50 Ω input impedance is transformed to a user-defined impedance value according to the selected "Pad Type": "Series-R"
(default) or "MLP" (Minimum Loss Pad)
(Default) The direct path is used automatically for frequencies close
to zero.
The analog mixer path is always used.
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YIG-Preselector
Enables or disables the YIG-preselector.
This setting requires an additional option R&S FSV3-B11 on the R&S FSV/A.
An internal YIG-preselector at the input of the R&S FSV/A ensures that image frequen-
cies are rejected. However, image rejection is only possible for a restricted bandwidth.
To use the maximum bandwidth for signal analysis, you can disable the YIG-preselector at the input of the R&S FSV/A, which can lead to image-frequency display.
Note: Note that the YIG-preselector is active only on frequencies greater than
7.5 GHz. Therefore, switching the YIG-preselector on or off has no effect if the fre-
quency is below that value.
For frequencies above 50 GHz (requires option R&S FSV3-B54G, for R&S FSVA3050
only), the YIG-preselector is automatically switched off (internally, not indicated in the
display). In this case, image frequencies can occur, as specified in the data sheet.
Note:
For the following measurements, the YIG-"Preselector" is off by default (if available).
●
I/Q Analyzer
●
GSM
●
VSA
Remote command:
INPut<ip>:FILTer:YIG[:STATe] on page 182
Configuration
Data input and output settings
Input Connector
Determines which connector the input data for the measurement is taken from.
"RF"
"RF Probe"
Remote command:
INPut<ip>:CONNector on page 181
5.3.1.2 Settings for input from I/Q data files
Access: "Overview" > "Input/Frontend" > "Input Source" > "I/Q File"
Or: [INPUT/OUTPUT] > "Input Source Config" > "Input Source" > "I/Q File"
(Default:) The "RF Input" connector
The "RF Input" connector with an adapter for a modular probe
This setting is only available if a probe is connected to the "RF Input"
connector.
It is not available for an active external frontend.
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For details, see Chapter 4.5, "Basics on input from I/Q data files", on page 43.
I/Q Input File State........................................................................................................ 63
Select I/Q data file.........................................................................................................63
I/Q Input File State
Enables input from the selected I/Q input file.
If enabled, the application performs measurements on the data from this file. Thus,
most measurement settings related to data acquisition (attenuation, center frequency,
measurement bandwidth, sample rate) cannot be changed. The measurement time
can only be decreased to perform measurements on an extract of the available data
only.
Note: Even when the file input is disabled, the input file remains selected and can be
enabled again quickly by changing the state.
Remote command:
INPut<ip>:SELect on page 183
Select I/Q data file
Opens a file selection dialog box to select an input file that contains I/Q data.
The I/Q data file must be in one of the following supported formats:
.iq.tar
●
.iqw
●
.csv
●
.mat
●
.wv
●
.aid
●
For details on formats, see Chapter C, "Reference: supported I/Q file formats",
on page 372.
Note: Only a single data stream or channel can be used as input, even if multiple
streams or channels are stored in the file.
Note: For some file formats that do not provide the sample rate and measurement time
or record length, you must define these parameters manually. Otherwise the traces are
not visible in the result displays.
The default storage location for I/Q data files is C:\R_S\INSTR\USER.
Configuration
Data input and output settings
Remote command:
INPut<ip>:FILE:PATH on page 184
5.3.1.3 External mixer settings
Access: [INPUT/OUTPUT] > "External Mixer Config"
If installed, the optional external mixer can be configured from the I/Q Analyzer application.
Special conversion loss tables (in .b5g or .b2g files) cannot be edited within the
R&S FSV/A firmware; they can only be imported and deleted.
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See Chapter 4.3.5, "External mixers and large bandwidth extension options",
on page 32
For details on using external mixers, see the R&S FSV/A User Manual.
● Mixer settings..........................................................................................................64
● Basic settings..........................................................................................................67
● Managing conversion loss tables............................................................................68
● Creating and editing conversion loss tables............................................................70
Mixer settings
Access: [INPUT/OUTPUT] > "External Mixer Config" > "Mixer Settings"
Configuration
Data input and output settings
External Mixer (State)................................................................................................... 64
RF Start / RF Stop.........................................................................................................65
Handover Freq.............................................................................................................. 65
Band..............................................................................................................................65
RF Overrange............................................................................................................... 65
Preset Band.................................................................................................................. 65
Mixer Type.....................................................................................................................66
Mixer Settings (Harmonics Configuration).................................................................... 66
└ Range 1/Range 2............................................................................................66
└ Harmonic Type................................................................................................66
└ Harmonic Order.............................................................................................. 66
└ Conversion Loss............................................................................................. 66
External Mixer (State)
Activates or deactivates the external mixer for input. If activated, "ExtMix" is indicated
in the channel bar of the application, together with the used band (see "Band"
on page 65).
Remote command:
[SENSe:]MIXer<x>[:STATe] on page 202
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RF Start / RF Stop
Displays the start and stop frequency of the selected band (read-only).
The frequency range for the user-defined band is defined via the harmonics configura-
tion (see "Range 1/Range 2" on page 66).
For details on available frequency ranges, see table 9-3 on page 205.
Remote command:
[SENSe:]MIXer<x>:FREQuency:STARt on page 204
[SENSe:]MIXer<x>:FREQuency:STOP on page 204
Handover Freq
If due to the LO frequency the conversion of the input signal is not possible using one
harmonic, the band must be split. An adjacent, partially overlapping frequency range
can be defined using different harmonics. In this case, the sweep begins using the harmonic defined for the first range. At the specified "handover frequency" in the overlapping range, it switches to the harmonic for the second range.
The handover frequency can be selected freely within the overlapping frequency
range.
Remote command:
[SENSe:]MIXer<x>:FREQuency:HANDover on page 203
Configuration
Data input and output settings
Band
Defines the waveguide frequency band or user-defined frequency band to be used by
the mixer.
The start and stop frequencies of the selected band are displayed in the "RF Start" and
"RF Stop" fields.
For a definition of the frequency range for the pre-defined bands, see table 9-3 on
page 205.
The mixer settings for the user-defined band can be selected freely. The frequency
range for the user-defined band is defined via the harmonics configuration (see "Range
1/Range 2" on page 66).
Remote command:
[SENSe:]MIXer<x>:HARMonic:BAND on page 205
RF Overrange
Sometimes, the harmonics defined for a specific band allow for an even larger frequency range than the band requires. By default, the pre-defined range is used. However, you can take advantage of the extended frequency range by overriding the
defined "RF Start" and "RF Stop" frequencies by the maximum values.
If "RF Overrange" is enabled, the frequency range is not restricted by the band limits
("RF Start" and "RF Stop"). In this case, the full frequency range that can be reached
using the selected harmonics is used.
Remote command:
[SENSe:]MIXer<x>:RFOVerrange[:STATe] on page 209
Preset Band
Restores the presettings for the selected band.
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Note: changes to the band and mixer settings are maintained even after using the
[PRESET] function. This function allows you to restore the original band settings.
Remote command:
[SENSe:]MIXer<x>:HARMonic:BAND:PRESet on page 204
Mixer Type
The External Mixer option supports the following external mixer types:
"2 Port"
"3 Port"
Remote command:
[SENSe:]MIXer<x>:PORTs on page 208
Mixer Settings (Harmonics Configuration)
The harmonics configuration determines the frequency range for user-defined bands
(see "Band" on page 65).
Range 1/Range 2 ← Mixer Settings (Harmonics Configuration)
Enables the use of one or two frequency ranges, where the second range is based on
another harmonic frequency of the mixer to cover the band's frequency range.
For each range, you can define which harmonic to use and how the conversion loss is
handled.
Remote command:
[SENSe:]MIXer<x>:HARMonic:HIGH:STATe on page 205
Configuration
Data input and output settings
LO and IF data use the same port
LO and IF data use separate ports
Harmonic Type ← Mixer Settings (Harmonics Configuration)
Defines if only even, only odd, or even and odd harmonics can be used for conversion.
Depending on this selection, the order of harmonic to be used for conversion changes
(see "Harmonic Order" on page 66). Which harmonics are supported depends on the
mixer type.
Remote command:
[SENSe:]MIXer<x>:HARMonic:TYPE on page 206
Harmonic Order ← Mixer Settings (Harmonics Configuration)
Defines which order of the harmonic of the LO frequencies is used to cover the frequency range.
By default, the lowest order of the specified harmonic type is selected that allows conversion of input signals in the whole band. If due to the LO frequency the conversion is
not possible using one harmonic, the band is split.
For the "USER" band, the order of harmonic is defined by the user. The order of harmonic can be between 3 and 128, the lowest usable frequency being 17.132 GHz.
Remote command:
[SENSe:]MIXer<x>:HARMonic[:LOW] on page 206
[SENSe:]MIXer<x>:HARMonic:HIGH[:VALue] on page 206
Conversion Loss ← Mixer Settings (Harmonics Configuration)
Defines how the conversion loss is handled. The following methods are available:
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Configuration
Data input and output settings
"Average"
"Table"
Remote command:
Average for range 1:
[SENSe:]MIXer<x>:LOSS[:LOW] on page 208
Table for range 1:
[SENSe:]MIXer<x>:LOSS:TABLe[:LOW] on page 208
Average for range 2:
[SENSe:]MIXer<x>:LOSS:HIGH on page 207
Table for range 2:
[SENSe:]MIXer<x>:LOSS:TABLe:HIGH on page 207
Basic settings
Access: [INPUT/OUTPUT] > "External Mixer Config" > "Basic Settings"
Defines the average conversion loss for the entire frequency range in
dB.
Defines the conversion loss via the table selected from the list. Predefined conversion loss tables are often provided with the external
mixer and can be imported to the R&S FSV/A. Alternatively, you can
define your own conversion loss tables. Imported tables are checked
for compatibility with the current settings before being assigned.
For details on conversion loss tables, see the External Mixer description in the R&S FSV/A User Manual.
For details on importing tables, see "Import Table" on page 69.
The basic settings concern general use of an external mixer. They are only available if
the External Mixer (State) is "On".
LO Level........................................................................................................................68
Signal ID/ Auto ID/ Auto ID Threshold...........................................................................68
Bias Value..................................................................................................................... 68
└ Write to CVL table...........................................................................................68
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LO Level
Defines the LO level of the external mixer's LO port. Possible values are from
13.0 dBm to 17.0 dBm in 0.1 dB steps. Default value is 15.5 dB.
Remote command:
[SENSe:]MIXer<x>:LOPower on page 203
Signal ID/ Auto ID/ Auto ID Threshold
Not available for the I/Q Analyzer application.
Bias Value
Define the bias current for each range, which is required to set the mixer to its optimum
operating point. It corresponds to the short-circuit current. The bias current can range
from -10 mA to 10 mA. The actual bias current is lower because of the forward voltage
of the mixer diode(s).
Tip: The trace in the currently active result display (if applicable) is adapted to the settings immediately so you can check the results.
To store the bias setting in the currently selected conversion loss table, select the Write
to CVL table button.
Remote command:
[SENSe:]MIXer<x>:BIAS[:LOW] on page 202
[SENSe:]MIXer<x>:BIAS:HIGH on page 202
Configuration
Data input and output settings
Write to CVL table ← Bias Value
Stores the bias setting in the currently selected "Conversion Loss Table" for the range.
If no conversion loss table is selected yet, this function is not available ("CVL Table not
selected").
(See "Conversion Loss" on page 66).
Remote command:
[SENSe:]CORRection:CVL:BIAS on page 210
Managing conversion loss tables
Access: [INPUT/OUTPUT] > "External Mixer Config" > "Conversion Loss Table"
In this tab, you configure and manage conversion loss tables. Conversion loss tables
consist of value pairs that describe the correction values for conversion loss at certain
frequencies. The correction values for frequencies between the reference points are
obtained via interpolation.
The currently selected table for each range is displayed at the top of the dialog box. All
conversion loss tables found in the instrument's C:\R_S\INSTR\USER\cvl\ directory are listed in the "Modify Tables" list.
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New Table..................................................................................................................... 69
Edit Table...................................................................................................................... 69
Delete Table.................................................................................................................. 69
Import Table.................................................................................................................. 69
Configuration
Data input and output settings
New Table
Opens the "Edit conversion loss table" dialog box to configure a new conversion loss
table.
Remote command:
[SENSe:]CORRection:CVL:SELect on page 213
Edit Table
Opens the "Edit conversion loss table" dialog box to edit the selected conversion loss
table.
Remote command:
[SENSe:]CORRection:CVL:SELect on page 213
Delete Table
Deletes the currently selected conversion loss table after you confirm the action.
Remote command:
[SENSe:]CORRection:CVL:CLEar on page 211
Import Table
Imports one or more stored conversion loss tables from any directory and copies them
to the instrument's C:\R_S\INSTR\USER\cvl\ directory. They can then be assigned
for use for a specific frequency range (see "Conversion Loss" on page 66).
Note:
Before copying any files to the C:\R_S\INSTR\USER\cvl\ directory, the R&S FSV/A
firmware moves any existing user-defined cvl tables to a backup subdirectory. To use
a user-defined cvl table later, select the file in the
C:\R_S\INSTR\USER\cvl\backup directory.
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Note: Measurements using bandwidth extension options over 400 MHz require special
conversion loss tables, see Chapter 4.3.5, "External mixers and large bandwidth exten-
sion options", on page 32.
Supported tables have the file extension *.b5g or *.b2g, as opposed to .acl for
common tables. While .acl files can be used, data acquisition with larger bandwidths
using such conversion loss tables leads to substantial inaccuracy. Using no conversion
loss tables at all during data acquisition with the larger bandwidth options causes even
more inaccuracy.
Note that only common conversion loss tables (in .acl files) can be edited. Special
conversion loss tables (in *.b5g or *.b2g files) can only be imported and deleted.
For more details, see Chapter 4.3.5, "External mixers and large bandwidth extension
options", on page 32.
Remote command:
MMEM:COPY '<conversionlosstable>',C:\R_S\INSTR\USER\cvl\
See R&S FSV3000/ FSVA3000 base unit user manual.
Creating and editing conversion loss tables
Configuration
Data input and output settings
Access: [INPUT/OUTPUT] > "External Mixer Config" > "Conversion Loss Table" >
"New Table" / "Edit Table"
Conversion loss tables can be newly defined and edited.
A preview pane displays the current configuration of the conversion loss function as
described by the position/value entries.
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Configuration
Data input and output settings
File Name......................................................................................................................71
Comment.......................................................................................................................72
Band..............................................................................................................................72
Harmonic Order.............................................................................................................72
Bias............................................................................................................................... 72
Mixer Name...................................................................................................................72
Mixer S/N...................................................................................................................... 72
Mixer Type.....................................................................................................................73
Position/Value................................................................................................................73
Insert Value................................................................................................................... 73
Delete Value..................................................................................................................73
Shift x............................................................................................................................ 73
Shift y............................................................................................................................ 73
Save..............................................................................................................................73
File Name
Defines the name under which the table is stored in the C:\R_S\INSTR\USER\cvl\
directory on the instrument. The name of the table is identical to the name of the file
(without extension) in which the table is stored. This setting is mandatory. The .ACL
extension is automatically appended during storage.
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Remote command:
[SENSe:]CORRection:CVL:SELect on page 213
Comment
An optional comment that describes the conversion loss table. The comment is userdefinable.
Remote command:
[SENSe:]CORRection:CVL:COMMent on page 211
Band
The waveguide or user-defined band to which the table applies. This setting is checked
against the current mixer setting before the table can be assigned to the range.
For a definition of the frequency range for the pre-defined bands, see table 9-3 on
page 205.
Remote command:
[SENSe:]CORRection:CVL:BAND on page 209
Harmonic Order
The harmonic order of the range to which the table applies. This setting is checked
against the current mixer setting before the table can be assigned to the range.
Remote command:
[SENSe:]CORRection:CVL:HARMonic on page 212
Configuration
Data input and output settings
Bias
The bias current which is required to set the mixer to its optimum operating point. It
corresponds to the short-circuit current. The bias current can range from -10 mA to
10 mA. The actual bias current is lower because of the forward voltage of the mixer
diode(s).
Tip: You can also define the bias interactively while a preview of the trace with the
changed setting is displayed, see "Bias Value" on page 68.
Remote command:
[SENSe:]CORRection:CVL:BIAS on page 210
Mixer Name
Specifies the name of the external mixer to which the table applies. This setting is
checked against the current mixer setting before the table can be assigned to the
range.
Remote command:
[SENSe:]CORRection:CVL:MIXer on page 212
Mixer S/N
Specifies the serial number of the external mixer to which the table applies.
The specified number is checked against the currently connected mixer number before
the table can be assigned to the range.
Remote command:
[SENSe:]CORRection:CVL:SNUMber on page 213
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Mixer Type
Specifies whether the external mixer to which the table applies is a two-port or threeport type. This setting is checked against the current mixer setting before the table can
be assigned to the range.
Remote command:
[SENSe:]CORRection:CVL:PORTs on page 212
Position/Value
Each position/value pair defines the conversion loss value in dB for a specific frequency. The reference values must be entered in order of increasing frequencies. A
maximum of 50 reference values can be entered. To enter a new value pair, select an
empty space in the "Position"/"Value" table, or select the Insert Value button.
Correction values for frequencies between the reference values are interpolated. Linear interpolation is performed if the table contains only two values. If it contains more
than two reference values, spline interpolation is carried out. Outside the frequency
range covered by the table, the conversion loss is assumed to be the same as for the
first and last reference value.
The current configuration of the conversion loss function as described by the position/
value entries is displayed in the preview pane to the right of the table.
Remote command:
[SENSe:]CORRection:CVL:DATA on page 211
Configuration
Data input and output settings
Insert Value
Inserts a new position/value entry in the table.
If the table is empty, a new entry at 0 Hz is inserted.
If entries already exist, a new entry is inserted above the selected entry. The position of
the new entry is selected such that it divides the span to the previous entry in half.
Delete Value
Deletes the currently selected position/value entry.
Shift x
Shifts all positions in the table by a specific value. The value can be entered in the edit
dialog box. The conversion loss function in the preview pane is shifted along the x-axis.
Shift y
Shifts all conversion loss values by a specific value. The value can be entered in the
edit dialog box. The conversion loss function in the preview pane is shifted along the yaxis.
Save
The conversion loss table is stored under the specified file name in the
C:\R_S\INSTR\USER\cvl\ directory of the instrument.
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5.3.1.4 External frontend settings
Access: "Overview" > "Input" > "Input Source Config" > "Input Source" > "External
Frontend"
The following settings are only available if the external frontend control option
(R&S FSV3-K553) is installed on the R&S FSV/A. They are only available for I/Qbased applications, such as the I/Q Analyzer application.
For details see the R&S FSV/A user manual.
● Global configuration settings...................................................................................74
● Frontend configuration settings...............................................................................76
● Diagnostics..............................................................................................................79
● Network configuration............................................................................................. 80
Global configuration settings
Access: "Overview" > "Input" > "Input Source Config" > "Input Source" > "External
Frontend" > "Global Config"
Configuration
Data input and output settings
In the global configuration settings, you define general settings for the connected external frontend. The general measurement setup is indicated for reference.
Global activation............................................................................................................75
External Frontend Connection State.............................................................................75
Frontend Type...............................................................................................................75
IP Address/ Computer Name........................................................................................ 75
FW Update....................................................................................................................76
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Global activation
If enabled, the R&S FSV/A allows you to configure and connect an external frontend.
The application adapts the available measurement settings to the connected frontend,
for example the available frequency range, reference level and attenuation. If no frontend is configured yet, the configuration settings become available. The channel bar
indicates "Inp: ExtFe".
If disabled, the frontend is disconnected. The application adapts the measurement settings to the common settings supported by the R&S FSV/A.
Remote command:
[SENSe:]EFRontend[:STATe] on page 193
External Frontend Connection State
Connects or disconnects the configured frontend for use in a measurement. Note that
this setting is only available if Global activation of external frontends is set to "On".
It can take up to 10 seconds to determine that LAN connection failed.
If disabled, the connection to the frontend is deactivated temporarily. A running mea-
surement is aborted, the measurement results are indicated as invalid. The measurement settings for the R&S FSV/A remain untouched.
Configuration
Data input and output settings
Remote command:
[SENSe:]EFRontend<fe>:CONNection[:STATe] on page 186
[SENSe:]EFRontend<fe>:CONNection:CSTate? on page 187
Frontend Type
Defines the type of frontend to be connected.
Currently, the R&S FSV/A supports the following external frontend types:
●
R&S FE44S
●
R&S FE50DTR
Remote command:
[SENSe:]EFRontend<fe>:CONNection:CONFig on page 187
IP Address/ Computer Name
The IP address or computer name of the frontend connected to the R&S FSV/A via
LAN. The IP address and computer name are indicated on the electronic ink display on
the side panel of the frontend.
By default, the TCPIP address is expected. To enter the computer name, toggle the
"123"/"ABC" button to "ABC".
Note: You can change the IP address of the connected frontend directly from the
R&S FSV/A, in the "Network configuration" on page 80.
Remote command:
[SENSe:]EFRontend<fe>:CONNection:CONFig on page 187
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FW Update
When the R&S FSV/A establishes a connection to the frontend, it checks the firmware
version of the frontend. If the R&S FSV/A does not support the firmware installed on
the frontend, you are asked to update the frontend firmware. You can either start the
firmware update immediately, or abort the connection process and update the firmware
on the frontend later. In this case, the frontend is not available for use with the
R&S FSV/A until you perform the update.
Remote command:
[SENSe:]EFRontend<fe>:FWUPdate on page 194
Frontend configuration settings
Access: "Overview" > "Input" > "Input Source Config" > "Input Source" > "External
Frontend" > "Frontend Config"
In the frontend configuration tab, frequency information on the connected frontend is
provided and you can configure the frequency response for the IF cable.
Configuration
Data input and output settings
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Mismatched settings on multiple connected instruments
Multiple instruments can be connected to and use the same frontend at the same time.
The frequency conversion settings are identical for all connected instruments. Thus, if
you change a frequency setting on one instrument while the other is performing a measurement, the measurement results no longer match the original measurement settings. In this case, an error message is displayed ("Settings mismatch"). To restore the
original measurement settings on the frontend, change a frontend setting in the
R&S FSV/A dialog.
Only one instrument can access the frontend to change settings at a time. While one
connected instrument changes hardware settings on the external frontend, the frontend
is locked for the other connected instrument. The second instrument gets a "Device
busy" message and must retry when the frontend is available again. In this case, start
a new measurement to access the frontend and change the settings.
Frequency Band Configuration..................................................................................... 77
Frequency Band............................................................................................................78
Reference Frequency....................................................................................................78
Intermediate Frequency................................................................................................ 78
Correction State............................................................................................................ 78
Load Cable Correction S2p File....................................................................................78
Configuration
Data input and output settings
Frequency Band Configuration
Defines the intermediate frequency (output) range of the external frontend.
The used Intermediate Frequency and the resulting Frequency Band sideband that can
be analyzed on the R&S FSV/A are indicated for reference.
The selected frequency band configuration is also indicated in the channel bar.
FE50DTR-type frontends can be used by an analyzer and a signal generator simulta-
neously. In this case, both channels use the same internal LO and thus both signal
paths operate on the same frequency. Therefore, if you want to analyze the signal from
the generator using the same frontend, make sure that the configured frequency bands
are identical on both instruments.
To use the extended analysis bandwidth option B1000, the external frontend must
downconvert all RF input signals to an IF frequency above 7.5 GHz. In this case, you
must set the frequency band to "IF High".
You can select the required IF output range manually, or it can be determined automatically, according to the other frequency settings.
In auto mode, for bandwidths ≤400 MHz, "IF Low" is used. For bandwidths larger than
400 MHz, "IF High" is used.
In manual mode, select one of the following IF output ranges:
"IF High"
A higher intermediate frequency is used on the external frontend,
resulting in a higher input frequency at the R&S FSV/A.
"IF Low"
A lower intermediate frequency is used on the external frontend,
resulting in a lower input frequency at the R&S FSV/A.
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Remote command:
[SENSe:]EFRontend<fe>:FREQuency:BCONfig:AUTO on page 189
[SENSe:]EFRontend<fe>:FREQuency:BCONfig:LIST? on page 189
[SENSe:]EFRontend<fe>:FREQuency:BCONfig:SELect on page 190
Frequency Band
Displays the range of the frequency band supported by the connected frontend (for reference only).
Note: To use the R&S FSV3-B1000 bandwidth extension, make sure that the resulting
frequency band is above 7.5 GHz. If necessary, change the "Frequency Band Configu-
ration" on page 77 setting.
Remote command:
[SENSe:]EFRontend<fe>:FREQuency:BAND:COUNt? on page 188
[SENSe:]EFRontend<fe>:FREQuency:BAND<b>:LOWer? on page 188
[SENSe:]EFRontend<fe>:FREQuency:BAND<b>:UPPer? on page 188
Reference Frequency
Sets the reference frequency that is used for frequency conversion on the frontend.
Depending on the connected type of frontend, different values are available.
Remote command:
[SENSe:]EFRontend<fe>:FREQuency:REFerence on page 191
[SENSe:]EFRontend<fe>:FREQuency:REFerence:LIST? on page 191
Configuration
Data input and output settings
Intermediate Frequency
Indicates the currently used intermediate frequency (IF) and sideband (upper/lower) for
frequency conversion (for reference only). This value depends on the "Frequency Band
Configuration" on page 77.
To use the extended analysis bandwidth option B1000, make sure that the used intermediate frequency is above 7.5 GHz.
For FE50DTR-type frontends that are used by an analyzer and a signal generator
simultaneously, make sure that the used intermediate frequency is identical on both
instruments.
"USB"
"LSB"
Remote command:
[SENSe:]EFRontend<fe>:FREQuency:IFRequency[:VALue]? on page 191
[SENSe:]EFRontend<fe>:FREQuency:IFRequency:SIDeband? on page 190
Correction State
Activates correction of the IF signal due to cable loss from the frontend to the analyzer.
Remote command:
[SENSe:]EFRontend<fe>:ALIGnment<ch>:STATe on page 194
Load Cable Correction S2p File
Opens a common file selection dialog to load correction data to compensate for signal
losses in the cable occurring at different IF signal frequencies.
Upper sideband
Lower sideband
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To provide valid results, the frequency response file must provide the S21 parameter
for the used frequency range of the external frontend.
Frequency response files are usually provided with the IF cable. The calibration data
for the IF cable provided with the R&S FSV/A is installed on the instrument at the factory.
The .s2p files are stored on the instrument under
C:\R_S\INSTR\USER\external_frontends\<frontend_type>\
touchstonefiles\. For example, the files for the IF cable are stored under
C:\R_S\Instr\user\external_frontends\FE44S\touchstonefiles\
if_default_cable_1347_7552_00.s2p.
Remote command:
[SENSe:]EFRontend<fe>:ALIGnment<ch>:FILE on page 193
Diagnostics
Access: "Overview" > "Input" > "Input Source Config" > "Input Source" > "External
Frontend" > "Diagnostics"
The "Diagnostics" tab provides information on the performance of the connected frontend and allows you to perform a self-test on the frontend.
Configuration
Data input and output settings
Start Selftest..................................................................................................................79
Abort Selftest.................................................................................................................80
Selftest Results............................................................................................................. 80
Start Selftest
Performs a self-test on the frontend to compare the current performance and characteristic values with the specified values for the frontend.
Remote command:
[SENSe:]EFRontend<fe>:SELFtest? on page 195
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Abort Selftest
Aborts a running self-test.
Remote command:
[SENSe:]EFRontend<fe>:SELFtest? on page 195
Selftest Results
Indicates the results of a selftest performed on the connected frontend.
Remote command:
[SENSe:]EFRontend<fe>:SELFtest:RESult? on page 195
Network configuration
Access: "Overview" > "Input" > "Input Source Config" > "Input Source" > "External
Frontend" > "Network Config"
After connection, you can assign a static IP address or switch to a dynamic IP address
for the external frontend directly from the R&S FSV/A.
Configuration
Data input and output settings
IP Address.....................................................................................................................80
Subnet Mask................................................................................................................. 81
DHCP............................................................................................................................81
Apply Network Settings.................................................................................................81
IP Address
Defines the IP address of the external frontend. If the DHCP server is used ("DHCP
On"), the setting is read-only.
Remote command:
[SENSe:]EFRontend<fe>:NETWork on page 192
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Subnet Mask
Defines the subnet mask of the external frontend. If the DHCP server is used ("DHCP
On"), this setting is read-only.
Remote command:
[SENSe:]EFRontend<fe>:NETWork on page 192
DHCP
Switches between DHCP server available (""On) or not available ("Off"). If a DHCP
server is available in the network, the IP address and subnet mask of the external frontend are obtained automatically from the DHCP server.
Remote command:
[SENSe:]EFRontend<fe>:NETWork on page 192
Apply Network Settings
Any changes to the external frontend network configuration are applied.
Beware that if you change the network information, the connection is aborted and you
must re-establish a connection to the frontend (see "External Frontend Connection
State" on page 75).
Remote command:
[SENSe:]EFRontend<fe>:NETWork on page 192
Configuration
Data input and output settings
5.3.1.5 Probe settings
Access: [INPUT / OUTPUT] > "Input Source Config" > "Probes"
Data input for the measurement can be provided by probes if the optional R&S RT-ZA9
adapter is used.
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The detected type of probe, if any, is displayed.
For more information on using probes with an R&S FSV/A, see Chapter 4.2, "Using
probes", on page 25.
For general information on the R&S®RT probes, see the device manuals.
Name.............................................................................................................................82
Serial Number............................................................................................................... 82
Part Number..................................................................................................................82
Type.............................................................................................................................. 82
Mode............................................................................................................................. 82
Common Mode Offset / Diff. Mode Offset / P Offset / N Offset /................................... 83
Attenuation....................................................................................................................83
Microbutton Action........................................................................................................ 83
Name
Probe name
Remote command:
[SENSe:]PROBe<pb>:SETup:NAME? on page 218
Configuration
Data input and output settings
Serial Number
Serial number of the probe
Remote command:
[SENSe:]PROBe<pb>:ID:SRNumber? on page 216
Part Number
Rohde & Schwarz part number
Remote command:
[SENSe:]PROBe<pb>:ID:PARTnumber? on page 216
Type
Type of probe:
●
Single-ended
●
Differential
●
Active Modular
Remote command:
[SENSe:]PROBe<pb>:SETup:TYPE? on page 220
Mode
Mode for multi-mode modular probes. Determines which voltage is measured.
"DM-mode"
"CM-mode"
"P-mode"
"N-mode"
Remote command:
[SENSe:]PROBe<pb>:SETup:PMODe on page 219
Voltage between the positive and negative input terminal
Mean voltage between the positive and negative input terminal vs.
ground
Voltage between the positive input terminal and ground
Voltage between the negative input terminal and ground
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Common Mode Offset / Diff. Mode Offset / P Offset / N Offset /
Sets the offset for the probe, depending on the used mode (CM and DM mode both
use the "Common Mode Offset"). The setting is only available if a differential (R&S RTZD) or modular (R&S RT-ZM) probe is connected to the R&S FSV/A.
If the probe is disconnected, the offset of the probe is reset to 0.0 V.
Note: If the offset for DM-mode or CM-mode is changed, the offsets for the P-mode
and N-mode are adapted accordingly, and vice versa.
Remote command:
[SENSe:]PROBe<pb>:SETup:CMOFfset on page 217
[SENSe:]PROBe<pb>:SETup:DMOFfset on page 217
[SENSe:]PROBe<pb>:SETup:NMOFfset on page 219
[SENSe:]PROBe<pb>:SETup:PMOFfset on page 220
Attenuation
Defines the attenuation applied to the input at the probe. This setting is only available
for modular probes.
"10:1"
"2:1"
Remote command:
[SENSe:]PROBe<pb>:SETup:ATTRatio on page 217
Configuration
Data input and output settings
Attenuation by 20 dB
Attenuation by 6 dB
Microbutton Action
Active Rohde & Schwarz probes (except for R&S RT-ZS10E) have a configurable
microbutton on the probe head. By pressing this button, you can perform an action on
the instrument directly from the probe.
Select the action that you want to start from the probe:
"Run Single"
"No Action"
Remote command:
[SENSe:]PROBe<pb>:SETup:MODE on page 218
5.3.1.6 External generator control settings
Access: [INPUT/OUPUT] > "External Generator Config"
The "External Generator" settings are available if the R&S FSV/A External Generator
Control option is installed. For each measurement channel, you can configure one
external generator. To switch between different configurations, define multiple measurement channels.
For more information on external generator control, see Chapter 4.4, "Basics on exter-
nal generator control", on page 33.
Starts one data acquisition.
Prevents unwanted actions due to unintended usage of the microbut-
ton.
● Interface configuration settings............................................................................... 84
● Measurement settings.............................................................................................86
● Source calibration functions....................................................................................88
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Interface configuration settings
For more information on configuring interfaces, see the "Remote Control Interfaces and
Protocols" section in the R&S FSV/A User Manual.
Configuration
Data input and output settings
Generator Type.............................................................................................................84
Interface........................................................................................................................ 84
TTL Handshake.............................................................................................................84
TCPIP Address / Computer Name................................................................................85
Reference......................................................................................................................85
Edit Generator Setup File..............................................................................................85
Frequency Min/ Frequency Max....................................................................................85
Level Min/ Level Max.................................................................................................... 85
Generator Type
Selects the generator type and thus defines the generator setup file to use.
For an overview of supported generators, see Chapter 4.4.2, "Overview of supported
generators", on page 36. For information on generator setup files, see Chapter 4.4.3,
"Generator setup files", on page 37.
Remote command:
SYSTem:COMMunicate:RDEVice:GENerator<gen>:TYPE on page 226
Interface
Type of interface connection used.
For details on which signal generators support which interfaces, see the documenta-
tion of the corresponding signal generator.
●
TCP/IP
Remote command:
SYSTem:COMMunicate:RDEVice:GENerator<gen>:INTerface on page 226
TTL Handshake
If available for the specified generator type, this option activates TTL synchronization
via handshake.
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Using the TTL interface allows for considerably higher measurement rates, because
the frequency stepping of the R&S FSV/A is directly coupled with the frequency stepping of the generator.
For more information on TTL synchronization, see "TTL synchronization" on page 41.
For an overview of which generators support TTL synchronization see Chapter 4.4.2,
"Overview of supported generators", on page 36.
TCPIP Address / Computer Name
TCP/IP address of the signal generator
Remote command:
SYSTem:COMMunicate:TCPip:RDEVice:GENerator<gen>:ADDRess
on page 226
Reference
Selects the internal R&S FSV/A or an external frequency reference to synchronize the
R&S FSV/A with the generator (default: internal).
Remote command:
SOURce<si>:EXTernal<gen>:ROSCillator[:SOURce] on page 225
Configuration
Data input and output settings
Edit Generator Setup File
Displays the setup file for the currently selected Generator Type in read-only mode in
an editor.
Although the existing setup files are displayed in read-only mode in the editor, they can
be saved under a different name (using "File > SaveAs").
Be careful, however, to adhere to the required syntax and commands. Errors are only
detected and displayed when you try to use the new generator (see also Chapter 4.4.8,
"Displayed information and errors", on page 42).
For details, see Chapter 4.4.3, "Generator setup files", on page 37.
Frequency Min/ Frequency Max
For reference only: Lower and upper frequency limit for the generator.
Level Min/ Level Max
For reference only: Lower and upper power limit for the generator.
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Measurement settings
Configuration
Data input and output settings
Source State................................................................................................................. 86
Source Power................................................................................................................86
Source Offset................................................................................................................ 86
Source Frequency Coupling..........................................................................................87
(Manual) Source Frequency..........................................................................................87
(Automatic) Source Frequency (Numerator/Denominator/Offset).................................87
Result Frequency Start................................................................................................. 88
Result Frequency Stop..................................................................................................88
Source State
Activates or deactivates control of an external generator.
Remote command:
SOURce<si>:EXTernal<gen>[:STATe] on page 224
Source Power
The output power of the external generator. The default output power is -20 dBm. The
range is specified in the data sheet.
Remote command:
SOURce<si>:EXTernal<gen>:POWer[:LEVel] on page 224
Source Offset
Constant level offset for the external generator. Values from -200 dB to +200 dB in 1
dB steps are allowed. The default setting is 0 dB. Offsets are indicated by the "LVL"
label in the channel bar (see also Chapter 4.4.8, "Displayed information and errors",
on page 42).
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Using this offset, attenuators or amplifiers at the output connector of the external generator can be considered. This is useful, for example, for the displayed output power
values on screen or during data entry. Positive offsets apply to an amplifier, while negative offsets apply to an attenuator after the external generator.
Remote command:
SOURce<si>:POWer[:LEVel][:IMMediate]:OFFSet on page 225
Source Frequency Coupling
Defines the frequency coupling mode between the R&S FSV/A and the generator.
For more information on coupling frequencies, see Chapter 4.4.7, "Coupling the fre-
quencies", on page 40.
"Auto"
"Manual"
Remote command:
SOURce<si>:EXTernal<gen>:FREQuency:COUPling[:STATe] on page 222
Configuration
Data input and output settings
Default setting: a series of frequencies is defined (one for each
sweep point), based on the current frequency at the RF input of the
R&S FSV/A (see "(Automatic) Source Frequency (Numerator/Denom-
inator/Offset)" on page 87). The RF frequency range covers the cur-
rently defined span of the R&S FSV/A (unless limited by the range of
the signal generator).
The generator uses a single fixed frequency, defined by (Manual)
Source Frequency which is displayed when you select "Manual" cou-
pling.
(Manual) Source Frequency
Defines the fixed frequency to be used by the generator.
Remote command:
SOURce<si>:EXTernal<gen>:FREQuency on page 221
(Automatic) Source Frequency (Numerator/Denominator/Offset)
With automatic frequency coupling, a series of frequencies is defined (one for each
sweep point), based on the current frequency at the RF input of the R&S FSV/A.
However, the frequency used by the generator can differ from the input from the
R&S FSV/A. The RF frequency can be multiplied by a specified factor, or a frequency
offset can be added, or both.
Note: The input for the generator frequency is not validated, i.e. you can enter any values. However, if the allowed frequency ranges of the generator are exceeded, an error
message is displayed on the R&S FSV/A. The values for Result Frequency Start and
Result Frequency Stop are corrected to comply with the range limits.
The value range for the offset depends on the selected generator. The default setting is
0 Hz. Offsets <> 0 Hz are indicated by the "FRQ" label in the channel bar. Negative
offsets can be used to define reverse sweeps.
For more information on coupling frequencies and reverse sweeps, see Chapter 4.4.7,
"Coupling the frequencies", on page 40. For more information on error messages and
the channel bar, see Chapter 4.4.8, "Displayed information and errors", on page 42.
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Remote command:
SOURce<si>:EXTernal<gen>:FREQuency[:FACTor]:DENominator
on page 222
SOURce<si>:EXTernal<gen>:FREQuency[:FACTor]:NUMerator on page 223
SOURce<si>:EXTernal<gen>:FREQuency:OFFSet on page 224
Result Frequency Start
For reference only: The start frequency for the generator, calculated from the configured generator frequency and the start value defined for the R&S FSV/A.
Result Frequency Stop
For reference only: The stop frequency for the generator, calculated from the configured generator frequency and the stop value defined for the R&S FSV/A.
Source calibration functions
The calibration functions of the external generator are available only if external generator control is active (see "Source State" on page 86).
Configuration
Data input and output settings
Calibrate Transmission..................................................................................................89
Calibrate Reflection Short............................................................................................. 89
Calibrate Reflection Open.............................................................................................89
Normalization state....................................................................................................... 89
Recall Cal. Settings.......................................................................................................89
Save as Trd Factor........................................................................................................90
Reference Position........................................................................................................90
Reference Value............................................................................................................90
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Calibrate Transmission
Starts a transmission type measurement to determine a reference trace. This trace is
used to calculate the difference for the normalized values.
Remote command:
[SENSe:]CORRection:METHod on page 228
Calibrate Reflection Short
Starts a short-circuit reflection type measurement to determine a reference trace for
calibration.
If both calibrations (open circuit, short circuit) are carried out, the calibration trace is
calculated by averaging the two measurements. The order of the two calibration measurements is irrelevant.
Remote command:
[SENSe:]CORRection:METHod on page 228
Selects the reflection method.
[SENSe:]CORRection:COLLect[:ACQuire] on page 227
Starts the sweep for short-circuit calibration.
Configuration
Data input and output settings
Calibrate Reflection Open
Starts an open-circuit reflection type measurement to determine a reference trace for
calibration.
If both reflection-type calibrations (open circuit, short circuit) are carried out, the reference trace is calculated by averaging the two measurements. The order of the two calibration measurements is irrelevant.
Remote command:
[SENSe:]CORRection:METHod on page 228
Selects the reflection method.
[SENSe:]CORRection:COLLect[:ACQuire] on page 227
Starts the sweep for open-circuit calibration.
Normalization state
Switches the normalization of measurement results on or off. This function is only
available if the memory contains a reference trace, that is, after a calibration has been
performed.
For details on normalization, see Chapter 4.4.5, "Normalization", on page 38.
Remote command:
[SENSe:]CORRection[:STATe] on page 229
Recall Cal. Settings
Restores the settings that were used during source calibration. This can be useful if
instrument settings were changed after calibration (e.g. center frequency, frequency
deviation, reference level, etc.).
Remote command:
[SENSe:]CORRection:RECall on page 228
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Save as Trd Factor
Uses the normalized measurement data to generate a transducer factor. The trace
data is converted to a transducer with unit dB and stored in a file with the specified
name and the suffix .trd under
C:\Program Files\Rohde-Schwarz\FSV3000\<version>\trd. The frequency
points are allocated in equidistant steps between start and stop frequency.
The generated transducer factor can be further adapted using the "Transducer" function in the [Setup] menu.
For more information on transducers, see the "General Instrument Setup > Transducers" section in the R&S FSV/A User Manual.
Note: Note that the normalized measurement data is used, not the reference trace!
Thus, if you store the normalized trace directly after calibration, without changing any
settings, the transducer factor is 0 dB for the entire span (by definition of the normalized trace).
Remote command:
[SENSe:]CORRection:TRANsducer:GENerate on page 229
Configuration
Data input and output settings
Reference Position
Defines the position of the reference line in percent of the total y-axis range.
The top of the diagram is 100%, the bottom is 0%. By default, the 0 dB line is displayed
at the top of the diagram (100%).
This setting is only available if normalization is on (see " Normalization state"
on page 89).
The reference line defined by the reference value and reference position is similar to
the Reference Level defined in the "Amplitude" settings. However, this reference line
only affects the y-axis scaling in the diagram, it has no effect on the expected input
power level or the hardware settings.
The normalized trace (0 dB directly after calibration) is displayed on this reference line,
indicated by a red line in the diagram. If you shift the reference line, the normalized
trace is shifted, as well.
Remote command:
DISPlay[:WINDow<n>][:SUBWindow<w>]:TRACe<t>:Y[:SCALe]:RPOSition
on page 254
Reference Value
Defines an offset for the position of the reference line.
This setting can be used to shift the reference line and thus the normalized trace, simi-
lar to the Shifting the Display (Offset) defined in the "Amplitude" settings shifts the reference level in the display.
Shifting the normalized trace is useful, for example, to reflect an attenuation or gain
caused by the measured DUT. If you then zoom into the diagram around the normalized trace, the measured trace still remains fully visible.
Remote command:
DISPlay[:WINDow<n>][:SUBWindow<w>]:TRACe<t>:Y[:SCALe]:RVALue
on page 227
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5.3.2 Output settings
Access: [Input/Output] > "Output"
The R&S FSV/A can provide output to special connectors for other devices.
For details on connectors, refer to the R&S FSV/A Getting Started manual, "Front /
Rear Panel View" chapters.
How to provide trigger signals as output is described in detail in the R&S FSV/A User
Manual.
Configuration
Data input and output settings
Noise Source Control....................................................................................................91
Noise Source Control
Enables or disables the 28 V voltage supply for an external noise source connected to
the "Noise source control / Power sensor") connector. By switching the supply voltage
for an external noise source on or off in the firmware, you can enable or disable the
device as required.
External noise sources are useful when you are measuring power levels that fall below
the noise floor of the R&S FSV/A itself, for example when measuring the noise level of
an amplifier.
In this case, you can first connect an external noise source (whose noise power level is
known in advance) to the R&S FSV/A and measure the total noise power. From this
value, you can determine the noise power of the R&S FSV/A. Then when you measure
the power level of the actual DUT, you can deduct the known noise level from the total
power to obtain the power level of the DUT.
Remote command:
DIAGnostic:SERVice:NSOurce on page 242
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5.4 Amplitude
Access: "Overview" > "Amplitude"
Amplitude settings are identical to the Spectrum application, except for a new scaling
function for I/Q Vector and Real/Imag results (see "Y-Axis Max" on page 97).
For background information on amplitude settings see the R&S FSV/A User Manual.
5.4.1 Amplitude settings
Access: "Overview" > "Amplitude"
Amplitude settings determine how the R&S FSV/A must process or display the expected input power levels.
Using external frontends
For an active external frontend, the amplitude settings refer to the RF input at the
external frontend, not the levels at the RF input of the R&S FSV/A. Electronic attenuation, preamplifier, and noise cancellation are not available. Input coupling is always DC.
Impedance is always 50 Ω.
Configuration
Amplitude
Reference Level............................................................................................................93
└ Shifting the Display (Offset)............................................................................ 93
└ Unit..................................................................................................................93
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└ Setting the Reference Level Automatically (Auto Level).................................94
RF Attenuation.............................................................................................................. 94
└ Attenuation Mode / Value................................................................................94
Using Electronic Attenuation.........................................................................................95
Input Settings................................................................................................................ 95
└ Preamplifier.....................................................................................................95
Reference Level
Defines the expected maximum reference level. Signal levels above this value are possibly not measured correctly. Signals above the reference level are indicated by an "IF
Overload" status display.
The reference level can also be used to scale power diagrams; the reference level is
then used for the calculation of the maximum on the y-axis.
Since the hardware of the R&S FSV/A is adapted according to this value, it is recommended that you set the reference level close above the expected maximum signal
level. Thus you ensure an optimal measurement (no compression, good signal-tonoise ratio).
Note that for input from the External Mixer (R&S FSV/A-B21) the maximum reference
level also depends on the conversion loss; see the R&S FSV3000/ FSVA3000 base
unit user manual for details.
For an active external frontend, the reference level refers to the RF input at the external frontend, not the levels at the RF input of the R&S FSV/A. The hardware is adjusted to the defined reference level optimally for input signals with a crest factor of 10 dB.
Thus, the required reference level for an optimal measurement can differ depending on
the crest factor of the input signal.
Remote command:
DISPlay[:WINDow<n>][:SUBWindow<w>]:TRACe<t>:Y[:SCALe]:RLEVel
on page 246
Configuration
Amplitude
Shifting the Display (Offset) ← Reference Level
Defines an arithmetic level offset. This offset is added to the measured level. In some
result displays, the scaling of the y-axis is changed accordingly.
Define an offset if the signal is attenuated or amplified before it is fed into the
R&S FSV/A so the application shows correct power results. All displayed power level
results are shifted by this value.
The setting range is ±200 dB in 0.01 dB steps.
Note, however, that the internal reference level (used to adjust the hardware settings to
the expected signal) ignores any "Reference Level Offset". Thus, it is important to keep
in mind the actual power level the R&S FSV/A must handle. Do not rely on the displayed reference level (internal reference level = displayed reference level - offset).
Remote command:
DISPlay[:WINDow<n>][:SUBWindow<w>]:TRACe<t>:Y[:SCALe]:RLEVel:
OFFSet on page 247
Unit ← Reference Level
The R&S FSV/A measures the signal voltage at the RF input.
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In the default state, the level is displayed at a power level of 1 mW (= dBm). Via the
known input impedance (50 Ω or 75 Ω, see "Impedance" on page 61), conversion to
other units is possible.
The following units are available and directly convertible:
●
dBm
●
dBmV
●
dBμV
●
dBμA
●
dBpW
●
Volt
●
Ampere
●
Watt
Remote command:
INPut<ip>:IMPedance on page 183
CALCulate<n>:UNIT:POWer on page 246
Setting the Reference Level Automatically (Auto Level) ← Reference Level
Automatically determines a reference level which ensures that no overload occurs at
the R&S FSV/A for the current input data. At the same time, the internal attenuators
are adjusted. As a result, the signal-to-noise ratio is optimized, while signal compression and clipping are minimized.
To determine the required reference level, a level measurement is performed on the
R&S FSV/A.
Configuration
Amplitude
If necessary, you can optimize the reference level further. Decrease the attenuation
level manually to the lowest possible value before an overload occurs, then decrease
the reference level in the same way.
You can change the measurement time for the level measurement if necessary (see
"Changing the Automatic Measurement Time (Meastime Manual)" on page 117).
Remote command:
[SENSe:]ADJust:LEVel on page 276
RF Attenuation
Defines the attenuation applied to the RF input of the R&S FSV/A.
Attenuation Mode / Value ← RF Attenuation
The RF attenuation can be set automatically as a function of the selected reference
level (Auto mode). Automatic attenuation ensures that no overload occurs at the RF
Input connector for the current reference level. It is the default setting.
By default and when no (optional) electronic attenuation is available, mechanical
attenuation is applied.
This function is not available for input from the optional "Digital Baseband" interface.
In "Manual" mode, you can set the RF attenuation in 1 dB steps (down to 0 dB). Other
entries are rounded to the next integer value. The range is specified in the data sheet.
If the defined reference level cannot be set for the defined RF attenuation, the reference level is adjusted accordingly and the warning "limit reached" is displayed.
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NOTICE! Risk of hardware damage due to high power levels. When decreasing the
attenuation manually, ensure that the power level does not exceed the maximum level
allowed at the RF input, as an overload can lead to hardware damage.
Remote command:
INPut<ip>:ATTenuation on page 247
INPut<ip>:ATTenuation:AUTO on page 248
Using Electronic Attenuation
If the (optional) Electronic Attenuation hardware is installed on the R&S FSV/A, you
can also activate an electronic attenuator.
In "Auto" mode, the settings are defined automatically; in "Manual" mode, you can
define the mechanical and electronic attenuation separately.
For an active external frontend, electronic attenuation is not available.
Note: Electronic attenuation is not available for stop frequencies (or center frequencies
in zero span) above 7 GHz.
In "Auto" mode, RF attenuation is provided by the electronic attenuator as much as
possible to reduce the amount of mechanical switching required. Mechanical attenuation can provide a better signal-to-noise ratio, however.
When you switch off electronic attenuation, the RF attenuation is automatically set to
the same mode (auto/manual) as the electronic attenuation was set to. Thus, the RF
attenuation can be set to automatic mode, and the full attenuation is provided by the
mechanical attenuator, if possible.
The electronic attenuation can be varied in 1 dB steps. If the electronic attenuation is
on, the mechanical attenuation can be varied in 5 dB steps. Other entries are rounded
to the next lower integer value.
If the defined reference level cannot be set for the given attenuation, the reference
level is adjusted accordingly and the warning "limit reached" is displayed in the status
bar.
Remote command:
INPut<ip>:EATT:STATe on page 250
INPut<ip>:EATT:AUTO on page 249
INPut<ip>:EATT on page 249
Configuration
Amplitude
Input Settings
Some input settings affect the measured amplitude of the signal, as well.
The parameters "Input Coupling" and "Impedance" are identical to those in the "Input"
settings.
See Chapter 5.3.1, "Input source settings", on page 59.
Preamplifier ← Input Settings
If the (optional) internal preamplifier hardware is installed, a preamplifier can be activated for the RF input signal.
You can use a preamplifier to analyze signals from DUTs with low output power.
For an active external frontend, a preamplifier is not available.
For R&S FSV/A3004, 3007, 3013, and 3030 models, the following settings are availa-
ble:
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Configuration
Amplitude
"Off"
"15 dB"
"30 dB"
Deactivates the preamplifier.
The RF input signal is amplified by about 15 dB.
The RF input signal is amplified by about 30 dB.
For R&S FSV/A44 or higher models, the input signal is amplified by 30 dB if the preamplifier is activated. In this case, the preamplifier is only available under the following
conditions:
●
In zero span, the maximum center frequency is 43.5 GHz
●
For frequency spans, the maximum stop frequency is 43.5 GHz
●
For I/Q measurements, the maximum center frequency depends on the analysis
bandwidth:
≤
43.5 GHz - (<Analysis_bw> / 2)
f
center
If any of the conditions no longer apply after you change a setting, the preamplifier is
automatically deactivated.
Remote command:
INPut<ip>:GAIN:STATe on page 251
INPut<ip>:GAIN[:VALue] on page 251
5.4.2 Scaling the y-axis
The individual scaling settings that affect the vertical axis are described here.
Access: "Overview" > "Amplitude" > "Scale" tab
Or: [AMPT] > "Scale Config"
Range............................................................................................................................97
Ref Level Position......................................................................................................... 97
Scaling.......................................................................................................................... 97
Y-Axis Max.................................................................................................................... 97
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Range
Defines the displayed y-axis range in dB.
The default value is 100 dB.
Remote command:
DISPlay[:WINDow<n>][:SUBWindow<w>]:TRACe<t>:Y[:SCALe] on page 252
Ref Level Position
Defines the reference level position, i.e. the position of the maximum AD converter
value on the level axis in %.
0 % corresponds to the lower and 100 % to the upper limit of the diagram.
Values from -120 % to +600 % are available. Larger values are useful for small scales,
such as a power range of 10 dB or 20 dB, and low signal levels, for example 60 dB
below the reference level. In this case, large reference level position values allow you
to see the trace again.
Remote command:
DISPlay[:WINDow<n>][:SUBWindow<w>]:TRACe<t>:Y[:SCALe]:RPOSition
on page 254
Configuration
Amplitude
Scaling
Defines the scaling method for the y-axis.
"Logarithmic"
"Linear with
Unit"
"Linear Percent"
"Absolute"
"Relative"
Remote command:
DISPlay[:WINDow<n>][:SUBWindow<w>]:TRACe<t>:Y:SPACing on page 254
DISPlay[:WINDow<n>][:SUBWindow<w>]:TRACe<t>:Y[:SCALe]:MODE
on page 253
Y-Axis Max
Defines the maximum value of the y-axis in the currently selected diagram in either
direction (in Volts). Thus, the y-axis scale starts at -<Y-Axis Max> and ends at +<Y-Axis
Max>.
This command is only available if the evaluation mode for the I/Q Analyzer is set to
"I/Q-Vector" or "Real/Imag (I/Q)".
Remote command:
DISPlay[:WINDow<n>][:SUBWindow<w>]:TRACe<t>:Y[:SCALe] on page 252
Logarithmic scaling (only available for logarithmic units - dB..., and A,
V, Watt)
Linear scaling in the unit of the measured signal
Linear scaling in percentages from 0 to 100
The labeling of the level lines refers to the absolute value of the reference level (not available for "Linear Percent")
The scaling is in dB, relative to the reference level (only available for
logarithmic units - dB...). The upper line of the grid (reference level) is
always at 0 dB.
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5.5 Frequency settings
Access: "Overview" > "Frequency"
Configuration
Frequency settings
Center Frequency......................................................................................................... 98
Center Frequency Stepsize...........................................................................................98
Frequency Offset...........................................................................................................98
Center Frequency
Defines the center frequency of the signal in Hertz.
The allowed range of values for the center frequency depends on the frequency span.
span > 0: span
f
and span
max
/2 ≤ f
min
depend on the instrument and are specified in the data sheet.
min
center
≤ f
max
– span
min
/2
Remote command:
[SENSe:]FREQuency:CENTer on page 255
Center Frequency Stepsize
Defines the step size by which the center frequency is increased or decreased using
the arrow keys.
The step size can be coupled to another value or it can be manually set to a fixed
value.
"= Center"
Sets the step size to the value of the center frequency. The used
value is indicated in the "Value" field.
"Manual"
Defines a fixed step size for the center frequency. Enter the step size
in the "Value" field.
Remote command:
[SENSe:]FREQuency:CENTer:STEP on page 255
Frequency Offset
Shifts the displayed frequency range along the x-axis by the defined offset.
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This parameter has no effect on the instrument's hardware, on the captured data, or on
data processing. It is simply a manipulation of the final results in which absolute frequency values are displayed. Thus, the x-axis of a spectrum display is shifted by a
constant offset if it shows absolute frequencies. However, if it shows frequencies relative to the signal's center frequency, it is not shifted.
A frequency offset can be used to correct the display of a signal that is slightly distorted
by the measurement setup, for example.
The allowed values range from -1 THz to 1 THz. The default setting is 0 Hz.
Remote command:
[SENSe:]FREQuency:OFFSet on page 256
5.6 Trigger settings
Access: "Overview" > "Trigger"( > "Trigger In/Out")
Trigger settings determine when the input signal is measured.
Configuration
Trigger settings
External triggers from one of the "TRIGGER INPUT/OUTPUT" connectors on the
R&S FSV/A are configured in a separate tab of the dialog box.
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Conventional gating as in the Spectrum application is not available for the I/Q Analyzer; however, a special gating mode is available in remote control, see Chap-
ter 9.4.4.3, "Configuring I/Q gating", on page 264.
For step-by-step instructions on configuring triggered measurements, see the
R&S FSV/A User Manual.
Trigger Source.............................................................................................................100
└ Trigger Source.............................................................................................. 100
└ Trigger Level.................................................................................................103
└ Repetition Interval.........................................................................................103
└ Drop-Out Time.............................................................................................. 103
└ Trigger Offset................................................................................................103
└ Hysteresis..................................................................................................... 104
└ Trigger Holdoff.............................................................................................. 104
└ Slope.............................................................................................................104
Trigger 1/2...................................................................................................................104
└ Output Type.................................................................................................. 105
Configuration
Trigger settings
└ Free Run.............................................................................................101
└ External Trigger 1/2............................................................................ 101
└ IF Power............................................................................................. 101
└ I/Q Power............................................................................................101
└ RF Power............................................................................................102
└ Power Sensor..................................................................................... 102
└ Time....................................................................................................102
└ Level................................................................................................... 105
└ Pulse Length.......................................................................................106
└ Send Trigger.......................................................................................106
Trigger Source
The trigger settings define the beginning of a measurement.
Trigger Source ← Trigger Source
Selects the trigger source. If a trigger source other than "Free Run" is set, "TRG" is displayed in the channel bar and the trigger source is indicated.
For gated measurements in sweep mode, only external triggers are allowed as the gating trigger source.
For an active external frontend, only external triggers, I/Q power triggers and (periodic)
time triggers are supported as trigger sources. See "External Frontend Connection
State" on page 75.
Note: If the 1 GHz or 600 MHz bandwidth extension options (B1000/B600) are active,
only an external trigger, IF power trigger or no trigger is available for bandwidths
≥400 MHz. If any other trigger is active and the analysis bandwidth is increased above
400 MHz (thus activating the B1000/B600 option), the trigger is automatically deactivated.
Remote command:
TRIGger[:SEQuence]:SOURce on page 260
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