R&S®FSV/A3000 I/Q Analyzer
and I/Q Input Interfaces
User Manual
(;ÜãT2)
1178853602
Version 10
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.
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
5User Manual 1178.8536.02 ─ 10
R&S®FSV/A3000 I/Q Analyzer
Contents
6User Manual 1178.8536.02 ─ 10
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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R&S®FSV/A3000 I/Q Analyzer
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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R&S®FSV/A3000 I/Q Analyzer
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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R&S®FSV/A3000 I/Q Analyzer
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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