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R&S®FS-K130PC
Distortion Analysis Software
User Manual
(;×;Ì<)
1173.1162.12 ─ 03
User Manual
Test & Measurement
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This manual covers the following products:
●
R&S®FS-K130PC (1310.0090.02)
© 2014 Rohde & Schwarz GmbH & Co. KG
Mühldorfstr. 15, 81671 München, Germany
Phone: +49 89 41 29 - 0
Fax: +49 89 41 29 12 164
E-mail: 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.
Trade names are trademarks of the owners.
The following abbreviations are used throughout this manual: R&S®FS-K130PC is abbreviated as R&S FS-K130PC.
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R&S®FS-K130PC
1 Documentation Overview......................................................................5
2 Welcome to R&S FS-K130PC................................................................6
2.1 System Requirements.................................................................................................. 6
2.2 Installing the Software..................................................................................................7
2.3 Using the Smart Card Reader.................................................................................... 11
2.4 Starting the Software.................................................................................................. 13
2.5 Adding Windows to the Working Area......................................................................16
2.6 Customizing the User Interface................................................................................. 23
2.7 Using the Help System............................................................................................... 24
2.8 Using Support Functions........................................................................................... 25
Contents
Contents
3 Measurements and Result Displays...................................................30
3.1 Recording a Reference Signal................................................................................... 30
3.2 Graphical Measurement Results............................................................................... 33
3.3 Selecting Traces..........................................................................................................45
3.4 Numerical Measurement Results...............................................................................46
4 Configuring and Performing Measurements..................................... 56
4.1 Performing Measurements.........................................................................................56
4.2 Configuring Instruments............................................................................................ 57
4.3 Configuring the Measurement................................................................................... 58
4.4 Defining the DSP Properties...................................................................................... 94
4.5 Specifying the File Type........................................................................................... 107
5 Analyzing Measurement Results......................................................115
5.1 Selecting the Evaluation Method.............................................................................115
5.2 Configuring Measurement Results..........................................................................116
5.3 Scaling the Axis........................................................................................................ 122
5.4 Handling Trace Data................................................................................................. 122
5.5 Using the Marker....................................................................................................... 123
6 Remote Control Example.................................................................. 126
Index....................................................................................................127
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R&S®FS-K130PC
Contents
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R&S®FS-K130PC
1 Documentation Overview
Documentation Overview
The documentation of the R&S FS-K130PC consists of the following parts:
User Manual
The user manual provides a detailed description of the R&S FS-K130PC functions.
It covers the following topics:
●
installing and launching the R&S FS-K130PC
●
setting up the R&S FS-K130PC in general
●
setting up the R&S FS-K130PC for measurements
●
performing measurements with the R&S FS-K130PC
Online Help
The online help provides quick access directly through the software interface to all
information necessary to work with the R&S FS-K130PC.
It covers the same topics as the user manual.
Note that you need Microsoft Internet Explorer 4.0 or higher to properly view chm files.
If certain security patches for operating system Windows XP® are installed, viewing
the chm file from a network resource is not possible. Open the online help in a hard
disk directory for correct indication of the help pages.
Internet
The R&S FS-K130PC website provides the latest versions of the software and the documentation and information for the R&S FS-K130PC.
If you have any questions about the software or suggestions, send an email to FS-
K130@rohde-schwarz.com
Release Notes
The release notes provide information about new and modified functions and eliminated problems.
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2 Welcome to R&S FS-K130PC
Welcome to R&S FS-K130PC
System Requirements
● System Requirements...............................................................................................6
● Installing the Software...............................................................................................7
● Using the Smart Card Reader.................................................................................11
● Starting the Software...............................................................................................13
● Adding Windows to the Working Area.....................................................................16
● Customizing the User Interface...............................................................................23
● Using the Help System............................................................................................24
● Using Support Functions.........................................................................................25
2.1 System Requirements
You need the following minimum system configuration to use R&S FS-K130PC:
Operating System: Microsoft Windows XP Professional (+ SP2), Microsoft Windows
Vista or Microsoft Windows 7 (32 and 64 bit versions).
Free Hard Disk Space: 1 GB
Free RAM: ≥1 GB
Graphics Resolution: ≥XGA (1024x768 pixel)
USB: one free USB port to connect the smartcard reader
alternatively: a built-in smartcard reader to connect the the card in ISO/IEC 7810-ID-1
format
Measuring instrument connection:
●
Hardware: IEC/IEEE bus or LAN connection
●
Software: VISA driver, National Instruments VISA version ≥4.2, Agilent IO Libraries
Suite 15.1 or higher
The software supports the following Rohde & Schwarz spectrum and signal analyzers
and signal generators:
●
R&S®FSG
●
R&S®FSQ
●
R&S®FSU
●
R&S®FSUP
●
R&S®FSV
●
R&S®FSVR
●
R&S®FSW
●
R&S®SMBV
●
R&S®SMU
●
R&S®SMW
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R&S®FS-K130PC
Welcome to R&S FS-K130PC
Installing the Software
2.2 Installing the Software
Working with the R&S FS-K130PC requires the installation of the software itself and
the installation of several software components.
The best way to install the software and the required components is to use the browser
tool that is delivered with the software.
If you install the software from a CD-ROM, systems that support the "AutoRun" functionality of the MS Windows operating system, automatically start the browser. If the
system does not support the "AutoRun" feature or if you install the software from the
download package available on the internet, you have to start the browser manually.
.NET Framework
.NET Framework 2.0 or higher is required to run both the browser tool and the software.
If opening the browser tool results in an error message, install the .NET Framework.
The .NET Framework installer is available on the R&S FS-K130PC CD-ROM. It is also
part of the download package available on the R&S FS-K130PC product homepage.
▶ Start the dotnetfx.exe and follow the instructions of the installer.
► Start the "AutoRun.exe".
The R&S FS-K130PC opens the browser tool.
The browser tool provides several tabs. Each one contains different information
about the software (see number 2 to 5 in the picture below).
► Navigate to the "Installation" tab.
= Navigation and address bar
1
2 = Safety Instructions tab
3 = Software Installation tab
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Installing the Software
4 = Documentation tab
5 = Contact tab
6 = Tab menu
7 = Main window
The "Installation" tab has three categories in the tab menu:
●
Required Components
Contains a guide to install the software components that are necessary to run the
software.
●
Software Installation
Contains a guide to install the R&S FS-K130PC itself.
●
Release Notes
Contains the release notes that were issued with each software release.
2.2.1 Installing Required Components
You have to install several software components required to successfully run the software. All components are delivered with the R&S FS-K130PC.
Required components
●
Microsoft .NET Framework 2.0
●
Microsoft Visual C++ Runtime Library (a specific version delivered with the
R&S FS-K130PC)
●
MATLAB Component Runtime
R2012a (32-bit)
●
Intel IPP Library
Version 4.1
●
VISA
► Navigate to the "Required Components" category in the "Installation" tab.
= Check for .NET Framework installation
1
2 = Install .NET Framework
3 = Install other required components (MATLAB etc.)
4 = Install VISA
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Installing the Software
Installing software components
1. Click on the "R&S Framework Installer" link in the main window of the browser tool.
The browser tool opens a dialog box that contains an overview of the required
components. It also shows if you have to install them or not.
2. In the "Installation State" column, check if the corresponding software is already
installed.
● Ready to install
The software is installed after you have selected it in the "Install?" column.
● Ready to download
The R&S Framework installer was not able to find the installation file for the
corresponding software.
You have to get the program somewhere (for example download it off the internet) and install it manually.
Note that all components except the "Port Mapper" are mandatory.
Note that some installation routines may not confirm the installation by a message like
'Installation Finished'. Therefore it might be necessary to restart the framework installer
and check again, if all components are installed.
Installing VISA
It is also necessary to install VISA (Virtual Instrument Software Architecture) to access
instruments connected to the PC via IEEE or LAN bus.
It is recommended to use the National Instruments VISA driver. The National Instrument VISA driver CD is supplied together with the R&S FSPC. You can also visit http://
www.ni.com/visa to get the latest version for your operating system if you are licensed
to.
2.2.2 Installing R&S FS-K130PC
After installing all required components, you can install the R&S FS-K130PC.
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Installing the Software
► Navigate to the "Software Installation" category in the "Installation" tab.
1 = Install the analysis software
► Click on the "install the R&S FS-K130" link in the main window of the browser tool.
The installer performs the following actions:
●
Install the R&S FS-K130PC software including an uninstall tool
●
Create a Windows Start Menu entry (Programs ⇨ R&S Distortion Analysis Software)
●
Create a shortcut on the desktop (optional)
●
If necessary (the software will specifically ask you to), set the required environment
variables.
► Start the software via the Windows "Start Menu" entry or the shortcut on the desk-
top.
2.2.3 Deinstalling R&S FS-K130PC
You can uninstall the software itself via the uninstall tool available in the Windows
"Start Menu" folder or via "Add or Remove Software" in the Windows "Control Panel".
The Framework components have to be uninstalled manually via "Add or Remove Software" in the Windows "Control Panel".
Before uninstalling the components, make sure that no other software uses one of the
components.
The following components and programs have been installed:
●
Microsoft .NET Framework 2.0
●
Microsoft Visual C++ 2005 Redistributable
●
Matlab Component Runtime 7.11
●
Intel Integrated Performance Primitives RTI4.1
●
Rohde & Schwarz Distortion Analysis Software (R&S FS-K130PC)
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Using the Smart Card Reader
2.3 Using the Smart Card Reader
The software is licensed by a smart card licensing system. This licensing system
requires a smart card to be connected to the PC when you are using the software. The
smart card and dongle are available as separate products.
You can connect the smart card in two ways.
●
Connect the smart card in SIM format.
If you want to connect the smart card in SIM format, use the USB smart card
reader that is included in the delivery of the software.
●
Connect the smart card in its full format.
If you want to connect the smart card in full format, an interface compatible to the
card format is required.
The following devices are able to read the smart card in full format.
– smart card reader integrated in a keyboard
– smart card reader integrated in a notebook
– smart card reader integrated in a desktop PC (e.g. OMNIKEY)
– smart card reader connected to the computer via serial bus or USB (e.g. OMNI-
KEY)
– USB reader connected to a LAN-to-USB converter to distribute the license via
the network (e.g DIGI AnaywhereUSB/2)
Licensing support
If you have any difficulties with the licensing system, support is only assured when you
are using the USB smart card reader that is delivered with the smart card.
Using the USB smart card reader
1. Included in the delivery of the software is the smart card in full format and a smart
card reader.
2. Break out the smart card in SIM format.
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Using the Smart Card Reader
3. Insert the smart card into the smart card reader.
a) Turn the smart card reader in a way that the OMNIKEY label faces upward.
b) Insert the smart card with the chip face down and the angled corner facing
away from the reader.
4. Push the smart card into the reader as far as possible.
The smart card reader is ready for use on any USB interface.
When you connect the reader to the computer, MS Windows automatically installs
the necessary drivers. If not, you can install the drivers manually from the software
CD. The required files are stored in the directory \Install\USB SmartCard
Reader Driver Files. The driver files are named according to the processor
architecure for which they are designed. (OMNIKEY3x21_x86 or
OMNIKEY3x21_x64).
Information on drivers and driver updates are also included in the ReadMe.txt file
in the same directory as the drivers.
Locking the computer
If you have difficulties unlocking the computer while the smart card is connected
because MS Windows tries to get log-in information from the card after you have
locked the computer.
You can solve this issue by editing the system registry.
Automatic change
► Run DisableCAD.reg to change the registry entry automatically.
The file is in the same directory as the driver files.
Manual change
1. Open the Windows "Start Menu" and select the "Run" item.
2. Enter regedit into the dialog box to open the system registry.
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Starting the Software
3. Look for
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\
policies\system.
4. Set the value of DisableCad to 0.
Administration rights
Security policies of your network environment might prevent you from editing the system registry or installing drivers. Contact your IT administration in that case.
2.4 Starting the Software
► Start the software with the desktop icon or in the Windows Start menu.
In the Start menu, you can find the software under "Programs" ⇨ "R&S Distortion
Analysis Software".
The R&S FS-K130PC checks if all required components are installed on your computer.
After that, the actual GUI opens.
The GUI of R&S FS-K130PC in its default state looks like this:
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Welcome to R&S FS-K130PC
Starting the Software
1 = Menu Bar: contains general functions of the software
2 = Toolbar: contains general measurement functions
3 = Workspace: contains elements for user interaction
4 = Status Bar: contains the status of miscellaneous processes that the software performs
Presetting the software
All settings have been assigned predefined values.
► Select the "Preset" menu item from the "File" menu.
The software restores the predefined values for all settings.
SCPI command:
SYST:PRES
If you change a setting to a value other than the predefined one, the font of this setting
turns bold.
Preset state:
Changed state:
Loading and saving customized settings
If you have customized the values of any parameter, save that set of settings in a file
for quick access at a later time.
► Select the "Save Settings" menu item from the "File" menu.
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Starting the Software
The R&S FS-K130PC opens a dialog box to save the current measurement configuration in a file with the *.FS_K130_Config file extension .
The FS_K130_Config file format
The FS_K130_Config file format is, in effect, an xml file format. Therefore you can
open and edit the file with any editor capable of viewing xml files. However, if you want
to change settings externally, make sure to keep the structure consistent.
► Select the "Load Settings" menu item from the "File" menu.
The R&S FS-K130PC opens a dialog box to select a file containing a previously
saved measurement configuration.
Exporting data
In addition to the measurement configuration, the software allows you export various
other data, for example measurement results.
► Select the "Export" menu item from the "File" menu.
The R&S FS-K130PC opens a submenu to select the type of data you want to
export.
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Adding Windows to the Working Area
Exiting the software
► Select the "Exit" menu item from the "File" menu.
2.5 Adding Windows to the Working Area
In the initial state, the workspace is completely empty. You have to add windows manually as required. The R&S FS-K130PC provides several types of windows. This chapter gives a quick overview of the window types.
2.5.1 The Hardware Configuration
The "Hardware Configuration" window visualizes the signal flow over all (hardware)
components in the test setup. Each component of the test setup is represented as a
colored box. The lines in between visualize which components are connected.
Depending on the test setup, the "Hardware Configuration" element may show different
components and a different setup. Refer to the description of each hardware component for more information on its properties.
If you add the "Hardware Configuration" window, you can add it once.
► Select the "Hardware Configuration" menu item from the "Windows" menu.
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Adding Windows to the Working Area
The R&S FS-K130PC adds the "Hardware Configuration" window to the workspace.
The following components may be part of the "Hardware Configuration":
●
I/Q Generator
●
Input Mixer
●
DUT Input Attenuation
●
DUT
●
Simulation
●
DUT Output Attenuation
●
Output Mixer
●
I/Q Recorder
Quick software configuration
Clicking anywhere in the block diagram opens a dialog box that contains ten important
settings for quick configuration of a measurement.
2.5.2 Hardware Properties
Each hardware component has its own characteristics. "Properties" windows contain
all necessary characteristics of the corresponding hardware component.
If you add a "Properties" window, you can add one at a time.
► Click on the hardware component you want to set up.
The R&S FS-K130PC adds the corresponding "Properties" window to the workspace.
All "Properties" windows look similar.
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Adding Windows to the Working Area
1 = Title Bar: shows the name of the hardware component.
2 = Parameter Group: group of similar parameters.
3 = Parameter: individual parameters that you can configure.
4 = Parameter Description: short description of the selected parameter.
Parameter groups
Parameter groups are a set of parameters that serve a similar purpose or belong
together in a way. To get a better view of a "Properties" window, you can expand or
collapse a group of parameters.
► Click on the
or the symbol.
Parameters
A parameter changes a certain characteristic of the hardware component.
The left column contains the name of the parameter. The right column contains the
value belonging to that parameter.
A normal font in the right column means that the default value has been set. The font
turns bold if you use values other than the default ones.
► Click in the right column of the parameter you want to change.
The R&S FS-K130PC activates input for that parameter.
There are three types of input for a parameter.
●
Select an item from a dropdown list ( shows after selecting the parameter)
● Select a file from a standard Windows dialog box or open an extended dialog
box that contains complex software properties ( shows after selecting the
parameter)
● Enter a value or name as you require including or excluding the unit (field stays
empty, no icon shows). If you include a unit, you can use shortcuts, e.g. 'k' for
'kHz'.
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Adding Windows to the Working Area
Parameter description
The parameter description contains a short description of the selected parameter. You
can find a detailed description of each parameter in chapter 4, "Configuring and Per-
forming Measurements", on page 56. Pressing the F1 key while the parameter is
active opens a more detailed help.
For more information on the help system see chapter 2.7, "Using the Help System",
on page 24.
2.5.3 Measurement Results
Measurement results are available in graphical and numerical form.
2.5.3.1 Graphical Results
Graphical results or result displays visualize the results as traces in a diagram. Traces
may be lines or points.
You can add as many graphical result windows as you like.
►
Press the icon or select the "New Graphical Result Window" menu item from the
"Windows" menu.
The R&S FS-K130PC adds a new result window to the workspace.
= Title Bar: shows the currently selected combination of result display and evaluation method.
1
2 = Toolbar: configures the result display.
3 = Result Display: shows the measurement results in graphic form, including a legend for the traces.
There are several result displays available to choose from in order for you to view
the results from different perspectives.
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Adding Windows to the Working Area
You can configure result displays via its toolbar. The toolbar contains the following elements:
●
The flag (red or black) indicates whether the displayed measurement results are
valid or not.
●
to open the "DSP Properties" dialog box.
For more information see chapter 4.4, "Defining the DSP Properties",
on page 94.
●
to select the aspect of the result display.
For more information see chapter 3, "Measurements and Result Displays",
on page 30.
●
to select the evaluation method.
For more information see chapter 5.1, "Selecting the Evaluation Method",
on page 115.
●
to select the traces you want to see.
For more information see chapter 3, "Measurements and Result Displays",
on page 30.
●
to deselect all traces.
●
to show a line between the measurement points.
●
to add dots to every measurement point.
●
to automatically scale the diagram to the results after each measurement.
●
to zoom or unzoom the result display in order to fit in the screen.
●
to update the trace.
●
to freeze the result display in focus. All other result displays update the results
as defined. To stop the measurement in general use the button in the toolbar of
the main window.
●
to save the trace either in bitmap format or in vector format.
●
to export the trace data to the clipboard.
For more information see chapter 5, "Analyzing Measurement Results",
on page 115.
A right-click opens the context menu that contains additional functionality like the
zoom. For more information see chapter 5, "Analyzing Measurement Results",
on page 115.
2.5.3.2 Numerical Results
Numerical results show the results in a table.
If you add the "Numerical Results" window, you can add it once.
► Select the "Numerical Results" menu item from the "Windows" menu.
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Adding Windows to the Working Area
The R&S FS-K130PC adds numerical results table to the workspace.
1
= Title Bar
2 = Save HTML report button
3 = Result group: group of similar results
4 = Result: individual measurement result
5 = Yellow result: approximate result
6 = White result: check not possible, but result is valid
7 = Green result: valid result
8 = Red result: invalid result
2.5.4 Message Log
The message log provides information about the measurement process or errors during the measurement. By default, the "Message Log" element is always active after
starting R&S FS-K130PC.
► Select the "Message Log" menu item from the "Windows" menu.
You can copy the contents of the message log, for example, to file a problem report.
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Adding Windows to the Working Area
2.5.5 89604A Layout
If required, the software supports an Agilent 89604A mode.
If you turn it on, the user interface of the R&S FS-K130PC looks like the Agilent
89604A user interface.
1. Select the 89604A "Compatible Layout" menu item from the "Windows" menu.
The R&S FS-K130PC rearranges the user interface to resemble the 89604A software. In "Compatible" mode, the user interface consists of four graphical result displays.
2. Select the "89604A Footer" menu item from the "Windows" menu.
The R&S FS-K130PC adds and emulates the 89604A footer. The footer contains
numerical results and information about the measurement.
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Customizing the User Interface
2.6 Customizing the User Interface
In addition to adding and removing elements to and from the workspace, you can also
customize the layout of the user interface by docking elements to a particular position
of the working area, by adding a tab to an existing element or by altogether removing
an element from the user interface.
2.6.1 Docking Elements
1. Select an element in the title bar with the mouse and move it around until a docking
spot appears.
Docking spots look like this:
2. Move the mouse cursor over one of the possible docking spots.
The border of the docking spot turns blue. The screen area in which the element
will be positioned also turns blue.
3. Release the element.
The element docks itself to the corresponding area of the GUI.
2.6.2 Adding an Element as a Tab
1. Select an element with the mouse and move it over the center docking spot in an
area where another element already is.
2. Release the element.
The released element is added as a tab to the element.
The active tab always is in a lighter color than the others.
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Using the Help System
Note that tabs may be at the top of the window or at the bottom of the window,
depending on where the window is in the user interface.
3.
Select the tab you need by either clicking on the tab itself or by clicking on the
symbol and selecting the tab you need from the list.
2.6.3 Removing an Element from the GUI
► Select an element with the mouse, move it around and release it.
If you haven't docked the element or added it as a tab, it is floating around as an
individual window. You can also move the element completely out of the GUI and
work with it in an independent window (e.g. another monitor).
2.7 Using the Help System
The help system provides information about the functions of the software. It is available
in several formats.
●
Manual
The manual is the most substantial part of the documentation. In addition to a
detailed description of all elements of the software, it also contains information on
how to set up and perform various measurements and background information on
the software. The manual is available in pdf format. You'll find it on the CD that
comes with the software and can download it off the internet.
Note that the version available on the internet may contain more current information than that on the CD.
●
Online Help
Press the F1 key or select the "Help Contents" or "Index" menu item from the
"Help" menu in the menu bar.
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Using Support Functions
The "Help Contents" menu item opens the contents of the online help while the
"Index" menu item opens the index of the online help.
If you press the F1 key while an element of the user interface is selected (e.g. a
particular parameter in a dialog box), the software goes directly to the description
of that paramter.
The online help contains the same information as the manual.
●
Parameter Description
The dialog boxes contain a field at the bottom that shows a short description of the
property or parameter you have currently selected. This field is always active and
colored the way of the selected hardware component.
2.8 Using Support Functions
Support functions provide information on the software and system performance and
provide support in case of complications while using the software.
2.8.1 Debugging Tools
In case of problems using the software, use the debugging tools provided by the software.
► Select the "Options" menu item from the "Tools" menu.
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Using Support Functions
The R&S FS-K130PC opens the "Debug Properties" dialog box.
Debug Mode Active
Turns the debugging mode on and off.
Debug File Root
Shows the folder (including path) that contains the file that contains the debugging
results (LOG output).
The folder also contains the software executable.
Store Kernel Input
If active, the R&S FS-K130PC saves the DSP input files in case unexpected signal
processing events happen.
Problem solution for R&S customer support may be easier if you include these files in
the error report to reproduce the entire DSP flow with all data going into the DSP. The
DSP input file is stored in the "Debug File Root" folder.
Store Kernel Output
If active, the R&S FS-K130PC saves the DSP output files in case unexpected signal
processing events happen.
Problem solution for R&S customer support may be easier if you include these files in
the error report to reproduce the entire DSP flow with all data going out of the DSP.
The DSP output file is stored in the "Debug File Root" folder.
VISA Call Logging Depth
Defines the extent of logging of SCPI communication between PC and instrument.
Activate and use this feature to solve problems relating to remote control.
2.8.2 About the System
The performance of the R&S FS-K130PC depends on the system configuration you
are using. If the system does not meet the requirements, the R&S FS-K130PC may not
work correctly.
► Select the "About" menu item from the "Help" menu.
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Using Support Functions
The "About" message box contains an overview of the state of the system components
the R&S FS-K130PC requires (like memory usage or software versions). Use this information as a source to detect problems.
Start NI Spy
The "Start NISpy" button opens the NISpy software by National Instruments. NISpy is a
debug tool that you can use if you encounter bugs or problems with the remote control.
NISpy will compile an error report for your problem after pressing the "Record" button.
Save the report and send the file to Rohde & Schwarz customer support.
For more information on its functionality refer to the NISpy manual available at http://
www.ni.com or the online help of the NISpy software.
Note that you have to install NISpy before you can use this function. NISpy is one component of the National Instruments VISA software package.
2.8.3 License Information
The R&S FS-K130PC only works in combination with a valid license.
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Using Support Functions
► Select the "License Information" menu item from the "Help" menu.
The "License Information" dialog box contains several functions to manage R&S software licenses.
Check licenses
Scans the system for R&S licenses and updates the "Available Options" pane in the
dialog box.
Enter license key code
Opens an input field to add a new license to the system.
Process license file
Adds a new license to the system via xml file.
2.8.4 Release Notes
Release notes contain functionality that has been added since the last version of the
R&S FS-K130PC.
Release notes are also available on the CD and on the internet.
► Select the "Release Note" menu item from the "Help" menu.
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Using Support Functions
The R&S FS-K130PC opens the release notes. The file contains all release notes
that have been released since the first version of the software, including beta releases.
Exporting release notes
The "Save as RTF" button exports the release notes to a rtf file.
2.8.5 Direct Support
If you encounter problems that you cannot solve yourself, you can request support
from Rohde & Schwarz.
► Select the "Send a Support Mail" menu item from the "Help" menu.
The R&S FS-K130PC creates an empty email with a corresponding subject and
the support email address that you can use to send an error report.
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3 Measurements and Result Displays
Measurements and Result Displays
Recording a Reference Signal
● Recording a Reference Signal................................................................................ 30
● Graphical Measurement Results.............................................................................33
● Selecting Traces..................................................................................................... 45
● Numerical Measurement Results............................................................................46
3.1 Recording a Reference Signal
3.1.1 Using the Reference Signal Acquisition Wizard
The "Reference Signal Acquisition Wizard" provides functionality to capture a signal
directly from a signal generator and then use it as the reference signal.
Alternatively, you can use an artificial reference signal that you load into the R&S FSK130PC. For more information on how to handle files see chapter 4.5, "Specifying the
File Type", on page 107.
When you are using the acquisition wizard, basically all you need to know about the
signal is its center frequency. The wizard then records the signal, looks for the period
and runs averaging on the I/Q data.
► Select the "Reference Signal Acquisition Wizard" menu item from the "Tools"
menu.
The "Reference Signal Acquisition Wizard" dialog box opens.
3.1.1.1 Signal Acquisition
Defines the characteristics of the signal to capture and process.
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RF Frequency
Defines the center frequency of the signal you want to use as the reference signal.
Remote command:
not supported
Sampling Frequency
Defines the number of samples the wizard acquires during the sampling period (sample rate).
Remote command:
not supported
Sampling Time
Defines the length of the sample that the wizard records to get the reference signal
from.
Remote command:
not supported
Samples
Shows the number of samples that the wizard records and calculates the reference
signal from.
The number of samples results from the sampling frequency and the sampling time.
Remote command:
not supported
Use Wideband Measurement Path
Turns the wideband path for a higher measurement bandwidth on and off.
Note that a higher measurement bandwidth might add unwanted effects (e.g.
increased noise) to the measurement.
Wideband measurement paths are available with hardware options for the R&S FSQ,
R&S FSV and R&S FSW. For more information refer to the datasheet of the analyzers.
Remote command:
CONF:IQSINK:WBAN ON | OFF
Signal Is Pulsed
Selects if the signal the reference signal is based on is a pulsed signal or not.
Remote command:
not supported
3.1.1.2 Signal Processing
Defines the characteristics of the signal processing.
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Minimum Samples Per Period
Defines the number of samples that a reference signal period must include.
A reference signal period is one complete cycle of the signal used as reference signal
which will repeat at its end. If you are using a normal ARB file, the reference signal
period is the number of samples divided by the clock rate.
Remote command:
not supported
Maximum Periods
Defines the number of periods that a reference signal may include at most.
Remote command:
not supported
Pulse Detection Limit
Defines the level threshold for pulse detection.
If you have turned the detection of pulses in the reference signal on, the "Pulse Detection Limit" defines the minimum distance between the On and Off regions of supposed
pulses. A signal is detected as a pulse if the distance between an On and an Off region
is greater than the "Pulse Detection Limit".
Remote command:
CONF:DSP:MOD:PDET <numeric value>
3.1.1.3 Display Options
Capture Buffer On Failure Only
Turns the display of the complete capture buffer on and off.
When you turn this feature on, the complete capture buffer contents are displayed only
if no periodicity could be found within the signal.
When you turn this feature off, the complete capture buffer is always displayed, regardless if a valid periodic signal is detected or not.
Note that displaying the complete capture buffer in case of a high number of averages
may consume a lot of resources (memory and processing power).
Remote command:
not supported
3.1.1.4 Special Options
Store Raw Captured Signal
Turns the storage of the raw data of the reference signal that has been captured on
and off.
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When you turn this feature on, the software stores the selected reference signal in a
file as a 32-bit floating vector. The data sequence is IQIQIQ.... The file name is "RefWi-
zard_iqiq.iqw". The location of the file depends on the Debug File Root (by default, this
is the directory the software was installed in).
Remote command:
not supported
3.2 Graphical Measurement Results
The R&S FS-K130PC provides several result displays. Each result display shows a
certain aspect of the signal characteristics.
Each result display features a customized set of traces. A trace shows the results for a
particular signal. For more information see chapter 3.3, "Selecting Traces",
on page 45.
1.
Press the
icon or select the "New Graphical Result Window" menu item from the
"Windows" menu.
The R&S FS-K130PC adds a new result window to the workspace.
2.
Select the result display from the
dropdown menu in the toolbar of the
diagram.
This chapter contains a description of all available result displays, including the trace
types that are available for each result display.
● Capture Buffer.........................................................................................................33
● Power......................................................................................................................34
● Gain.........................................................................................................................36
● Constellation Diagram.............................................................................................38
● AM/AM.................................................................................................................... 40
● AM/PM.................................................................................................................... 41
● I and Q.................................................................................................................... 43
● EVM........................................................................................................................ 43
● Channel...................................................................................................................44
3.2.1 Capture Buffer
The capture buffer contains the raw data that has been recored during the first stage of
signal processing (usually the synchronization algorithm). The raw data contains the
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reference signal as well as the measurement signal. It is the source data for the synchronization and all further evaluations.
Both the reference signal and the measurement signal are shifted in time by the measured trigger delay of the synchronization algorithm. As both signals are matched in
the time domain in that case, you can compare them visually.
You can use the capture buffer result display to identify the causes for possible unexpected or invalid results.
The available trace types are as follows:
Reference Signal...........................................................................................................34
Measured Signal........................................................................................................... 34
Measured Signal with DPD........................................................................................... 34
Reference Signal
Shows the characteristics of the reference signal over time. The reference signal represents the ideal signal for your purposes (as selected and present at the DUT input).
For more information on generating a reference signal see chapter 3.1, "Recording a
Reference Signal", on page 30 and chapter 4.3.1, "Configuring the I/Q Generation",
on page 59.
Measured Signal
Shows the characteristics of the measured signal over time.
The measured signal represents the characteristics of the DUT you are testing.
Measured Signal with DPD
Shows the characteristics of the measured signal over time, including digital predistortion (DPD).
The measured signal represents the characteristics of the DUT you are testing.
3.2.2 Power
The "Power" result display shows the power of the signal over time after the synchronization process has been finished. You can examine the signal from various angles
within signal definition, measurement and processing flow.
The time period the software analyzes depends on the number of samples you have
set.
The available trace types are as follows:
Reference Signal...........................................................................................................35
Measured Signal........................................................................................................... 35
Modeled Signal............................................................................................................. 35
EVM (Reference Signal vs Measured Signal)...............................................................35
EVM (Measured Signal vs Modeled Signal)..................................................................35
Predistorted Signal........................................................................................................36
Measured Signal After DPD (Expected)........................................................................36
Measured Signal After DPD (Measured).......................................................................36
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Reference Signal
Shows the power characteristics of the reference signal. The reference signal represents the ideal signal for your purposes (as selected and present at the DUT input).
For more information on generating a reference signal see chapter 3.1, "Recording a
Reference Signal", on page 30 and chapter 4.3.1, "Configuring the I/Q Generation",
on page 59.
Measured Signal
Shows the power characteristics of the (synchronized) measured signal at the DUT
output.
The software uses this signal for the model estimation process.
To match both signals visually, you can eliminate the nominal gain of the measurement
signal. For more information see "Gain Normalization" on page 117.
For more information on the measurement configuration see chapter 4.3.8, "Configur-
ing the I/Q Recorder", on page 89.
Modeled Signal
Shows the power characteristics of the signal when the calculated model has been
applied to the reference signal.
If the model matches the behavior of the DUT, the characteristics of the signal are the
same as those of the measured signal (minus the noise).
For more information on supported models see chapter 4.4, "Defining the DSP Proper-
ties", on page 94.
EVM (Reference Signal vs Measured Signal)
Shows the error vector magnitude (EVM) between the reference signal and the measured signal.
To get useful results, the calculated linear gain is compensated to match both signals.
Depending on the DUT, noise and nonlinear effects may have been added to the measurement signal. These effects are visualized by this trace.
You can reduce the effects of noise by increasing the Periods to Capture. This runs an
averaging based on the complex data and thus reduces noise significantly.
In addition, if you are using the "Spectrum" evaluation, the trace shows the in-band distortion.
EVM (Measured Signal vs Modeled Signal)
Shows the error vector magnitude (EVM) between the modeled signal and the measured signal.
The EVM between the measured and modeled signal indicates the quality of the DUT
modeling. If the model matches the DUT behavior, the modeling error is zero (or is
merely influenced by noise).
This result display shows changes in the model and its parameters and thus allows you
to optimize the modeling.
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Predistorted Signal
Shows the signal that is applied to the DUT input, including digital predistortion (DPD)
and after the DUT has been modeled and the DPD function has been calculated.
The predistorted signal is the signal that - applied to the DUT input or used as the input
argument of the model function - creates an output signal at the DUT or model function
showing the linear gain version of the input signal. In mathematical terms this means
that if x=f(y) is the model function, the predistortion function a=p(b) is formed in such a
way that x=f(p(y)) results in x=G*y (with G being the linear gain factor).
If you are using the "Spectrum" evaluation, the DPD shows an increased ACP power
as it must compensate the ACP power of the nonlinear behavior of the DUT.
For more information on supported models see chapter 4.4, "Defining the DSP Proper-
ties", on page 94.
Measured Signal After DPD (Expected)
Shows the expected power characteristics of the output signal, including digital predistortion (DPD).
If both the model and the DPD are calculated correctly, the expected signal is a linear
amplified version of the reference signal.
Note: Because the DUT may get into high compression, the total RMS level may be
lower than the measured measured signal without DPD.
For more information on supported models see chapter 4.4, "Defining the DSP Proper-
ties", on page 94.
Measured Signal After DPD (Measured)
Shows the measured power characteristics of the output signal, including digital predistortion (DPD).
If this signal is different to the expected signal, this is usually an indicator that the DUT
does not behave according to the model or that the DPD is not possible with the
selected model function. To get a better signal including digital predistortion, try, for
example, to increase the model order or select the Volterra model instead of a polynomial model.
For more information on the measurement configuration see chapter 4.3.8, "Configur-
ing the I/Q Recorder", on page 89.
3.2.3 Gain
The "Gain" result display shows the amplification and error effects of the DUT as a
function of the DUT input or output power.
The gain is the ratio of the input and output power of the DUT.
Nonlinear effects typically result in a trace that drops near high power levels or does
not follow the ideal horizontal gain line also in low-level regions.
The available trace types are as follows:
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Gain vs Reference Signal............................................................................................. 37
Gain vs Measured Signal.............................................................................................. 37
Gain vs Reference - Model........................................................................................... 37
Gain vs Measured Signal after DPD (Expected)...........................................................37
Gain vs Measured Signal after DPD (Measured)..........................................................38
EVM vs Reference Signal............................................................................................. 38
Gain vs Measured Signal (shifted to the reference peak)............................................. 38
Gain vs Reference Signal
Shows the signal gain as a function of the reference signal power.
In case of nonlinear amplifiers or DUTs, the gain decreases if the input power becomes
too high to follow the linear part of the DUT characteristics. For very low levels, the
trace widens vertically due to noise influence.
Because of memory effects, the trace usually widens in the low-level and high-level
ranges. Memory effects typically show as slopes on the curve, ecspecially near high
ouput powers.
Gain vs Measured Signal
Shows the signal gain as a function of the measured signal power.
In case of nonlinear amplifiers or DUTs, the gain decreases if the input power becomes
too high to follow the linear part of the DUT characteristics. For very low levels, the
trace widens vertically due to noise influence.
Because of memory effects, the trace usually widens in the low-level and high-level
ranges. Memory effects typically show as slopes on the curve, ecspecially near high
ouput powers.
Gain vs Reference - Model
Shows the signal gain as a function of the signal used for the model estimation process.
If the DUT was modeled correctly, the trace should resemble the "Gain vs Ref" trace
minus noise.
Because of memory effects, the trace usually widens in the low-level and high-level
ranges. Memory effects typically show as slopes on the curve, ecspecially near high
ouput powers.
Gain vs Measured Signal after DPD (Expected)
Shows the expected signal gain as a function of the output signal including digital predistortion (DPD).
Because of memory effects, the trace usually widens in the low-level and high-level
ranges. Memory effects typically show as slopes on the curve, ecspecially near high
ouput powers.
Note: Because the DUT may get into high compression, the total RMS level may be
lower than the measured measured signal without DPD.
Available if you mix a DPD into the signal.
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Gain vs Measured Signal after DPD (Measured)
Shows the measured signal gain as a function of the output signal including digital predistortion (DPD).
Because of memory effects, the trace usually widens in the low-level and high-level
ranges. Memory effects typically show as slopes on the curve, ecspecially near high
ouput powers.
If this signal is different to the expected signal, this is usually an indicator that the DUT
does not behave according to the model or that the DPD is not possible with the
selected model function. To get a better signal including digital predistortion, try, for
example, to increase the model order or select the Volterra model instead of a polynomial model.
Available if you mix a DPD into the signal.
EVM vs Reference Signal
Shows the error vector magnitude (EVM) as a function of the reference signal power.
In case of nonlinear DUTs, the EVM increases if the is getting higher to follow the linear part of the DUT characteristics. Linear DUTs have wider and higher EVM only in
case of low powers because of the increasing influence of noise.
Gain vs Measured Signal (shifted to the reference peak)
Shows the gain as a function of the signal power that was actually measured.
Because of memory effects, the trace usually widens in the low-level and high-level
ranges. Memory effects typically show as slopes on the curve, ecspecially near high
ouput powers.
3.2.4 Constellation Diagram
The constellation diagram shows the complex values in an I/Q diagram and plots the
constellation for modulated signals (e.g. 16QAM).
The available trace types are as follows:
Reference Signal...........................................................................................................38
Measured Signal........................................................................................................... 39
Modeled Signal............................................................................................................. 39
EVM (Reference vs Measured Signal)..........................................................................39
Predistorted Signal........................................................................................................39
After DPD (Expected)....................................................................................................39
After DPD (Measured)...................................................................................................40
Reference Signal
Shows the constellation diagram for the reference signal. The reference signal represents the ideal signal for your purposes (as selected and present at the DUT input).
For more information on generating a reference signal see chapter 3.1, "Recording a
Reference Signal", on page 30 and chapter 4.3.1, "Configuring the I/Q Generation",
on page 59.
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Measured Signal
Shows the constellation diagram for the (synchronized) measured signal.
To match both signals visually, the nominal gain of the measurement signal can be
eliminated. For more information see "Gain Normalization" on page 117.
For more information on the measurement configuration see chapter 4.3.8, "Configur-
ing the I/Q Recorder", on page 89.
Modeled Signal
Shows the constellation diagram for the signal when the calculated model has been
applied to the reference signal.
If the model matches the behavior of the DUT, the characteristics of the signal are the
same as those of the measured signal (minus the noise).
For more information on supported models see chapter 4.4, "Defining the DSP Proper-
ties", on page 94.
EVM (Reference vs Measured Signal)
Shows the error vector magnitude (EVM) between the reference signal and the measured signal.
This constellation diagram allows you to, for example, see if noise is uniform or has a
special shape.
Predistorted Signal
Shows the signal that is applied to the DUT input, including digital predistortion (DPD)
and after the DUT has been modeled and the DPD function has been calculated.
The predistorted signal is the signal that - applied to the DUT input or used as the input
argument of the model function - creates an output signal at the DUT or model function
showing the linear gain version of the input signal. In mathematical terms this means
that if x=f(y) is the model function, the predistortion function a=p(b) is formed in such a
way that x=f(p(y)) results in x=G*y (with G being the linear gain factor).
If you are using the "Spectrum" evaluation, the DPD shows an increased ACP power
as it must compensate the ACP power of the nonlinear behavior of the DUT.
For more information on supported models see chapter 4.4, "Defining the DSP Proper-
ties", on page 94.
After DPD (Expected)
Shows the expected constellation diagram of the output signal, including digital predistortion (DPD).
If both the model and the DPD are calculated correctly, the expected signal is a linear
amplified version of the reference signal.
Note: Because the DUT may get into high compression, the total RMS level may be
lower than the measured measured signal without DPD.
For more information on supported models see chapter 4.4, "Defining the DSP Proper-
ties", on page 94.
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After DPD (Measured)
Shows the measured constellation diagram of the output signal, including digital predistortion (DPD).
If this signal is different to the expected signal, this is usually an indicator that the DUT
does not behave according to the model or that the DPD is not possible with the
selected model function. To get a better signal including digital predistortion, try, for
example, to increase the model order or select the Volterra model instead of a polynomial model.
For more information on the measurement configuration see chapter 4.3.8, "Configur-
ing the I/Q Recorder", on page 89.
3.2.5 AM/AM
The AM/AM result display is the display used to observe nonlinear effects with and
without memory. It shows the amplitude at the DUT output (or the signal processing
block if one is used for DPD) versus the amplitude at the DUT input.
Nonlinear effects typically result in a trace that flattens near high power levels or does
not follow the ideal straight line in low-level regions.
Memory effects typically show as slopes within the curve, especially near high output
powers.
The available trace types are as follows:
Measured Signal........................................................................................................... 40
Modeled Signal............................................................................................................. 40
DPD...............................................................................................................................40
After DPD (Expected)....................................................................................................41
After DPD (Measured)...................................................................................................41
Ideal Signal................................................................................................................... 41
Measured Signal
Shows the AM/AM characteristics of the measured signal at the DUT output.
The software uses this signal for the model estimation process.
For more information on the measurement configuration see chapter 4.3.8, "Configur-
ing the I/Q Recorder", on page 89.
Modeled Signal
Shows the AM/AM characteristics of the signal when the calculated model has been
applied to the reference signal.
If the model matches the behavior of the DUT, the characteristics of the signal are the
same as those of the measured signal (minus the noise).
For more information on supported models see chapter 4.4, "Defining the DSP Proper-
ties", on page 94.
DPD
Shows the signal that is applied to the DUT input, including digital predistortion (DPD)
and after the DUT has been modeled and the DPD function has been calculated.
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The predistorted signal is the signal that - applied to the DUT input or used as the input
argument of the model function - creates an output signal at the DUT or model function
showing the linear gain version of the input signal. In mathematical terms this means
that if x=f(y) is the model function, the predistortion function a=p(b) is formed in such a
way that x=f(p(y)) results in x=G*y (with G being the linear gain factor).
If you are using the "Spectrum" evaluation, the DPD shows an increased ACP power
as it must compensate the ACP power of the nonlinear behavior of the DUT.
For more information on supported models see chapter 4.4, "Defining the DSP Proper-
ties", on page 94.
After DPD (Expected)
Shows the expected AM/AM characteristics of the output signal, including digital predistortion (DPD).
If both the model and the DPD are calculated correctly, the expected signal is a linear
amplified version of the reference signal. In that case, the signal would be represented
by the following function.
y = Gain * x
For more information on supported models see chapter 4.4, "Defining the DSP Proper-
ties", on page 94.
After DPD (Measured)
Shows the measured AM/AM characteristics of the output signal, including digital predistortion (DPD).
For more information on the measurement configuration see chapter 4.3.8, "Configur-
ing the I/Q Recorder", on page 89.
Ideal Signal
Shows the ideal AM/AM characteristics of the signal at the DUT output.
3.2.6 AM/PM
The AM/PM result display is the display used to observe nonlinear effects with and
without memory. It shows the difference in phase between the DUT output and the
DUT input versus the input of the DUT.
Nonlinear effects typically result in a trace that not equal to zero near high power levels.
Memory effects typically show as slopes within the curve, especially near high output
powers.
The available trace types are as follows:
Measured Signal........................................................................................................... 42
Modeled Signal............................................................................................................. 42
Predistorted Signal........................................................................................................42
After DPD (Expected)....................................................................................................42
After DPD (Measured)...................................................................................................42
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Measured Signal
Shows the AM/PM characteristics of the measured signal at the DUT output.
The software uses this signal for the model estimation process.
For more information on the measurement configuration see chapter 4.3.8, "Configur-
ing the I/Q Recorder", on page 89.
Modeled Signal
Shows the AM/PM characteristics of the signal when the calculated model has been
applied to the reference signal.
If the model matches the behavior of the DUT, the characteristics of the signal are the
same as those of the measured signal (minus the noise).
For more information on supported models see chapter 4.4, "Defining the DSP Proper-
ties", on page 94.
Predistorted Signal
Shows the signal that is applied to the DUT input, including digital predistortion (DPD)
and after the DUT has been modeled and the DPD function has been calculated.
The predistorted signal is the signal that - applied to the DUT input or used as the input
argument of the model function - creates an output signal at the DUT or model function
showing the linear gain version of the input signal. In mathematical terms this means
that if x=f(y) is the model function, the predistortion function a=p(b) is formed in such a
way that x=f(p(y)) results in x=G*y (with G being the linear gain factor).
If you are using the "Spectrum" evaluation, the DPD shows an increased ACP power
as it must compensate the ACP power of the nonlinear behavior of the DUT.
For more information on supported models see chapter 4.4, "Defining the DSP Proper-
ties", on page 94.
After DPD (Expected)
Shows the AM/PM characteristics of the signal applied to the DUT input, including digital predistortion (DPD).
This predistorted signal is the inverted modeled signal and is thus a mirrored version of
the modeled signal. The mirror axis is represented by the following function.
y = 0
For more information on supported models see chapter 4.4, "Defining the DSP Proper-
ties", on page 94.
After DPD (Measured)
Shows the measured AM/PM characteristics of the output signal including digital predistortion (DPD).
For more information on the measurement configuration see chapter 4.3.8, "Configur-
ing the I/Q Recorder", on page 89.
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3.2.7 I and Q
The I and Q signals are separate representations of the complex measurement (input)
and reference (output) signal. They can be used, e.g. to judge the difference influence
of nonlinear effect in both I and Q chain of the DUT.
Reference I and Q.........................................................................................................43
Measured I and Q......................................................................................................... 43
Model I and Q................................................................................................................43
Reference I and Q
Shows the I or Q parts of the reference signal used for the model estimation process.
Measured I and Q
Shows the I or Q parts of the (synchronized) measured signal used for the model estimation process.
To match both signals visually, the nominal gain of the measurement signal can be
eliminated. For more information see "Gain Normalization" on page 117.
Model I and Q
Shows the I or Q parts of the signal used for the model estimation process.
3.2.8 EVM
The "EVM" result display shows the error vector magnitude of the signal over time. You
can examine the signal from various angles within signal definition, measurement and
processing flow.
The time period the software analyzes depends on the number of samples you have
set.
The available trace types are as follows:
Reference Signal vs Measured Signal.......................................................................... 43
Measured Signal vs Modeled Signal.............................................................................44
Reference Signal vs Signal after DPD (Expected)........................................................44
Reference Signal vs Signal after DPD (Measured).......................................................44
Reference Signal vs Measured Signal
Shows the error vector magnitude (EVM) between the reference signal and the measured signal.
To get useful results, the calculated linear gain is compensated to match both signals.
Depending on the DUT, noise and nonlinear effects may have been added to the measurement signal. These effects are visualized by this trace.
You can reduce the effects of noise by increasing the Periods to Capture. This runs an
averaging based on the complex data and thus reduces noise significantly.
For more information on generating a reference signal see chapter 3.1, "Recording a
Reference Signal", on page 30 and chapter 4.3.1, "Configuring the I/Q Generation",
on page 59.
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Measured Signal vs Modeled Signal
Shows the error vector magnitude (EVM) between the modeled signal and the measured signal.
The EVM between the measured and modeled signal indicates the quality of the DUT
modeling. If the model matches the DUT behavior, the modeling error is zero (or is
merely influenced by noise).
This result display shows changes in the model and its parameters and thus allows you
to optimize the modeling.
For more information on supported models see chapter 4.4, "Defining the DSP Proper-
ties", on page 94.
Reference Signal vs Signal after DPD (Expected)
Shows the expected error vector magnitude (EVM) between the reference signal and
the output signal, including digital predistortion.
Note: Because the DUT may get into high compression, the total RMS level may be
lower than the measured measured signal without DPD.
Reference Signal vs Signal after DPD (Measured)
Shows the measured error vector magnitude (EVM) between the reference signal and
the output signal, including digital predistortion.
If this signal is different to the expected signal, this is usually an indicator that the DUT
does not behave according to the model or that the DPD is not possible with the
selected model function. To get a better signal including digital predistortion, try, for
example, to increase the model order or select the Volterra model instead of a polynomial model.
3.2.9 Channel
The "Channel" result display shows the impulse response of the DUT.
You can use this display, for example, to analyze the filter frequency resonse when frequency filtering is dominant effect in the signal chain of the DUT.
Note that non-linear devices might show a weird impulse response.
For useful results, it is recommended to display the result as a spectrum.
The available trace types are as follows:
Amplitude...................................................................................................................... 44
Phase............................................................................................................................ 44
Amplitude
Shows the amplitude characteristics of the DUT's impulse response.
Phase
Shows the phase characteristics of the DUT's impulse response.
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Selecting Traces
3.3 Selecting Traces
For every result display the R&S FS-K130PC provides a customized set of traces. In
the result diagram, each trace is displayed in a different color. Above the diagram, the
R&S FS-K130PC shows a legend with the name and color of every active trace currently in the diagram. The labels of the axis are the same as that of the current evaluation method. The scaling may be different for each trace and is adjusted accordingly.
This chapter gives a short overview of the characteristics of all available traces.
1.
From the dopdown menu, select the trace you'd like to see.
Each currently active trace has a check mark in front of it ( ).
The same procedure also deselects individual traces.
2. Next to the trace selection dropdown menu is a deselect all traces function. Press-
ing the button clears the diagram from all traces.
For a more comprehensive reference of available traces see the description of the
result displays (chapter 3.2, "Graphical Measurement Results", on page 33).
Shortcuts
Instead of using the mouse to activate and deactivate a trace, you can also use shortcuts. The shortcuts are Ctrl-'number' with 'number' being the number of the trace as it
appears in the dropdown menu. So, for example, to display the DUT Model trace (the
5th in the dropdown menu) in the Power result display, the shortcut would be Ctrl-5.
The figure below shows the signal flow and the stage the corresponding traces result
from. The colors in the diagram correspond to the colors of the traces in the R&S FSK130PC.
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Fig. 3-1: Signal flow. The colors correspond to the traces you can view with the R&S FS-K130PC.
3.4 Numerical Measurement Results
The numerical results table contains the measurement results in numerical form. The
table always shows the same results, no matter what hardware configuration, aspect of
the result and evaluation method you are using.
► Select the "Numerical Results" menu item from the "Windows" menu.
The software opens the "Numerical Results" table.
Some results are colored to indicate if that result is feasible. Feasibility for each result
depends on a predefined value range for that result.
●
Green
Results are within the tolerance levels.
●
Yellow
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Results are not within the tolerance levels, but deviate only slightly.
●
Red
Results are not within the tolerance levels, and deviate considerably.
●
White
No tolerance levels have been defined for the results.
The numerical results are split into several result groups. Note that the first group is a
compilation of several results that would otherwise appear only at the end of the table.
Selecting a result group
Use the dropdown menu on the top to jump directly to a certain group of results.
● Power......................................................................................................................47
● Signal Synchronization............................................................................................49
● Intercepts................................................................................................................ 51
● Modulation Quality.................................................................................................. 53
● System Modeling.....................................................................................................53
● CCDF...................................................................................................................... 54
3.4.1 Power
Power results show various aspects of the power of the signal at the DUT input and
output.
DUT Input (RMS)
RMS power at the DUT input.
R&S FS-K130PC sets the input RMS power during the auto-level process. It is the
numerical (not measured) final output RMS power of the signal generator. The value is
corrected by the DUT input attenuation that you have set in the signal flow.
Note: If you have set a duty cycle, the RMS power is corrected by the duty cycle to
add to the RMS power during the ON time of the signal.
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For more information see
●
"Duty Cycle" on page 67
Remote command:
Query only: FETCH:NUM:POW:INP:RMS?
DUT Input (Peak)
Peak power at the DUT input.
R&S FS-K130PC calculates the input peak power from the input RMS power and the
crest factor of the signal. It is a numerical calculation, not the measured power.
Remote command:
Query only: FETCH:NUM:POW:INP:PEAK?
DUT Input (Crest)
Crest factor of the signal at the DUT input.
R&S FS-K130PC calculates this value from the relation of the input RMS power and
the input peak power.
Typically, the result is in the range from 4 to 8 dB for digitally modulated signals and
from 8 to 12 dB for OFDM signals. These results may vary.
The Crest factor at the DUT input is always 3 dB in case of dual tone signals and 0 dB
for CW signals.
Remote command:
Query only: FETCH:NUM:POW:INP:CRES?
DUT Output (RMS)
RMS power at the DUT output.
It is the power that the R&S FS-K130PC measures the output RMS power during the
auto-level process. It is the configured final output RMS power of the DUT after a successful auto-level procedure.
Note: If you have set a duty cycle, the RMS power is corrected by the duty cycle to
add to the RMS power during the ON time of the signal.
For more information see
●
"Duty Cycle" on page 67
Remote command:
Query only: FETCH:NUM:POW:OUT:RMS?
DUT Ouput (Peak)
Peak power at the DUT output.
It is the power the R&S FS-K130PC measures at the DUT output.
Remote command:
Query only: FETCH:NUM:POW:OUT:PEAK?
DUT Output (Crest)
Crest factor of the signal at the DUT output.
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R&S FS-K130PC calculates this value from the relation of the output RMS power and
the output peak power.
Because of nonlinear effects of the DUT, the crest factor at the DUT output is reduced
compared to the crest factor at the DUT input if the DUT enters the compression area.
Remote command:
Query only: FETCH:NUM:POW:OUT:CRES?
DUT Output (Leveling Error)
Level error between configured and measured RMS power at the DUT output.
During the auto-level process, R&S FS-K130PC adjusts the output RMS power to meet
the RMS output power you have specified. After a correct auto-level procedure this
result should be 0. However, a residual error can occur if, for example, the measurement bandwidth is not correct or if there are heavy nonlinear effects inside the DUT
(e.g. negative gain around the target RMS value). You can eliminate that issue by
adjusting the "Leveling Cycles" or the "Maximum Level Error".
For more information see
●
"Maximum Level Error" on page 80
●
"Leveling Cycles" on page 80
Remote command:
Query only: FETCH:NUM:POW:OUT:ERR?
3.4.2 Signal Synchronization
Signal synchronization results contain results that indicate the quality of the signal synchronization.
All errors are compensated by the synchronization algorithm.
Averages Executed
Number of I/Q reference signal data blocks used for averaging purposes.
Usually, the result should be the same as the average count you have set. Depnding
on the alignment of the reference signal relative to the measurement signal, however,
the number of averages can be one lower or one higher compared to the set value.
For more information see
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●
"Periods to Capture" on page 90
Remote command:
Query only: FETCH:NUM:SYNC:AVG?
Confidence
Quality of the synchronization of reference signal and measured signal.
Typically, the confidence should be above 97%. Heavy nonlinear effects can cause
lower values.
If the confidence is below 50%, it is likely that the reference and measurement signal
are completely different. Probable causes are that the generator output is not connected to the DUT input, that I and Q are swapped or a damaged DUT.
Remote command:
Query only: FETCH:NUM:SYNC:CONF?
Frequency Offset
Frequency difference of reference signal and measurement signal.
If the reference oscillators of signal generator and analyzer are not coupled, the two
internal 10 MHz OCXOs generate slightly different reference frequencies.
If the reference frequencies are coupled, the frequency offset should be about 0 Hz.
If the offset is very high, it is likely that
●
the reference frequency sources are not coupled correctly, e.g. if the analyzer is
configured for external reference frequency, but the cable is not connected.
●
the OCXO offsets are too high, especially if you are using custom signal generators instead of measurement signal generator like the R&S SMU.
Within the simulation mode, the frequency offset can be set as a simulation parameter.
Remote command:
Query only: FETCH:NUM:SYNC:FREQ?
Phase Offset
Phase offset between reference signal and measurement signal.
If you are using the RF path for measurements, the phase between reference and
measurement signal is random because the RF phases between signal generator and
analyzer are not locked, even if the reference frequencies are locked. This is a typical
behavior of two RF measurement instruments.
Remote command:
Query only: FETCH:NUM:SYNC:PHAS?
Trigger Offset
Offset between the trigger event and the start of the reference signal waveform.
Remote command:
Query only: FETCH:NUM:SYNC:TIME?
I/Q Offset
Shift of the ideal I/Q constellation in the I/Q plane.
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The I/Q offset value can be seen as a complex linear shift of the ideal I/Q constellation
points in the I/Q plane.
Remote command:
Query only: FETCH:NUM:SYNC:IQOF?
Gain Imbalance
Gain difference between the real (I) and imaginary (Q) part of the signal.
This effect is typically generated by two separate amplifiers in the I and Q path of the
analog baseband signal generation which have different gains.
Remote command:
Query only: FETCH:NUM:SYNC:GAIN?
Quadrature Error
Phase deviation of the 90° phase difference between I and Q.
Within a typical transmitter, the I and Q signal parts are mixed with an angle of 90° by
the IQ output mixer. Due to hardware imperfections, the signal delay of I and Q may be
different and thus lead to an angle non-equal to 90°.
Remote command:
Query only: FETCH:NUM:SYNC:QUAD?
I/Q Imbalance
Combination of Quadrature error and Gain imbalance.
The I/Q imbalance parameter is another representation of the combination of Quadrature error and gain imbalance.
Remote command:
Query only: FETCH:NUM:SYNC:IQIM?
3.4.3 Intercepts
Intercepts results contain results that show the characteristics of the signal at various
intercept points.
Gain
Ratio between the output and input RMS power of the DUT.
Remote command:
Query only: FETCH:NUM:INTE:GAIN?
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Compression
Ratio between the crest factor at the input and the output.
Compression typically cuts the peaks of the signal. This leads to a droop in crest factor
and thus positive compression values.
Remote command:
Query only: FETCH:NUM:INTE:COMP?
Maximum Linear Gain
Maximum possible (linear) gain of the amplifier with the control power that you have
defined.
When you compare the maximum possible gain with the gain that has been actually
measured, you can determine how far the amplifier is still away from the optimum or if
it has already past the compression point.
Remote command:
Query only: FETCH:NUM:INTE:LGAIN?
1 dB Compression Point (Input Level)
Input power level at which the output power drops 1 dB below the (theoretical) linear
output power.
To calculate the 1 dB compression point, the software evaluates the linear (small-signal) gain value from the measurement data and fits it to the low-power region. From
that it derives the intersection of the measured (non-linear) gain curve and a theoretical
linear gain curve whose gain is 1 dB lower.
Remote command:
Query only: FETCH:NUM:INTE:DB1C?
IIP3 / IIP5 / OIP3 / OIP5
3rd and 5th order intercept points, the value is either the power at the input (IIP) or at
the output (OIP).
To calculate the IPs, the software uses a polynomial model based on the measured
data (IPs are only defined for memory-free conditions). After the model has been calculated, the R&S FS-K130PC applies a dual-tone signal to the model, increases the
power of the signal and calculates its harmonic components (3rd and 5th order).
The intercept point Nth order is the point at which the power of the fundamental is the
same as the power of the Nth harmonic signal component.
Note: Intercept point calculation. If the DUT has no significant compression effect in
the measured input power region, the calculation of the IPs may fail.
Remote command:
IIP3 (query only): FETCH:NUM:INTE:IIP3?
IIP5 (query only): FETCH:NUM:INTE:IIP5?
OIP3 (query only): FETCH:NUM:INTE:OIP3?
OIP5 (query only): FETCH:NUM:INTE:OIP5?
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3.4.4 Modulation Quality
The modulation quality results contain results that show the error between the reference signal and the signal that has been measured.
EVM RMS
RMS value of the error vector magnitude between synchronized reference and measurement signal.
The result summary shows the EVM in dB and %.
An additional EVM RMS is shown in case you have applied the DPD to the signal (➙
Use Model For DPD). Note that the software captures additional I/Q data to calculate
the EVM after DPD.
Remote command:
EVM (query only): FETCH:NUM:MOD:EVM:RMS?
EVM after DPD (query only): FETCH:NUM:DPD:EVM:RMS?
EVM Peak
Peak value of the error vector magnitude between synchronized reference and measurement signal.
The result summary shows the EVM in dB and %.
An additional EVM Peak is shown in case you have applied the DPD to the signal (➙
Use Model For DPD). Note that the software captures additional I/Q data to calculate
the EVM after DPD.
Remote command:
EVM (query only): FETCH:NUM:MOD:EVM:PEAK?
EVM after DPD (query only): FETCH:NUM:DPD:EVM:PEAK?
3.4.5 System Modeling
System modeling results contain results that indicate the quality of the measured signal
compared to the modeled signal.
Mean Modeling Error
Mean error between the measured signal and the reference signal with the calculated
model applied.
The mean modeling error thus shows if the model is precise enough to describe the
real DUT behavior.
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Note that there are still some factors like the noise floor that have an effect on the
mean modeling error. These factors limit the quality of the results to a certain minimum
value.
Remote command:
Query only: FETCH:NUM:MOD:MERR:MEAN?
3.4.6 CCDF
The CCDF results contain results that show details of the CCDF evaluation.
DUT Input (Level Above RMS)
Percentage of all signal amplitudes that are higher then the reference signal RMS
level.
Remote command:
Query only: FETCH:NUM:CCDF:INP:RMS?
DUT Input (10% above, 1% above, 0.1% above, 0.01% above, 0.001% above)
X % of all signal amplitudes are N dB above the RMS level of the reference signal.
Remote command:
10 % (query only): FETCH:NUM:CCDF:INP:P10?
1 % (query only): FETCH:NUM:CCDF:INP:P1?
0.1 % (query only): FETCH:NUM:CCDF:INP:P0_1?
0.01 % (query only): FETCH:NUM:CCDF:INP:P0_01?
0.001 % (query only): FETCH:NUM:CCDF:INP:P0_001?
DUT Output (Level Above RMS)
Percentage of all signal amplitudes that are higher then the measured signal RMS
level.
Remote command:
Query only: FETCH:NUM:CCDF:OUT:RMS?
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DUT Output (10% above, 1% above, 0.1% above, 0.01% above, 0.001% above)
X % of all signal amplitudes are N dB above the RMS level of the measured signal.
Remote command:
10 % (query only): FETCH:NUM:CCDF:OUT:P10?
1 % (query only): FETCH:NUM:CCDF:OUT:P1?
0.1 % (query only): FETCH:NUM:CCDF:OUT:P0_1?
0.01 % (query only): FETCH:NUM:CCDF:OUT:P0_01?
0.001 % (query only): FETCH:NUM:CCDF:OUT:P0_001?
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4 Configuring and Performing Measurements
Configuring and Performing Measurements
Performing Measurements
● Performing Measurements......................................................................................56
● Configuring Instruments..........................................................................................57
● Configuring the Measurement.................................................................................58
● Defining the DSP Properties................................................................................... 94
● Specifying the File Type........................................................................................107
4.1 Performing Measurements
Without making any changes to the properties after starting the software the first time,
or after a preset, the R&S FS-K130PC measures a signal that is simulated internally.
In its default state, this noise-like signal has a 1 MHz bandwidth and a clock rate of
16 MHz. A noise level of 60 dBc, a timing offset of 50 samples and a frequency offset
of 100 Hz is applied to the signal. R&S FS-K130PC records 4096 samples for the evaluation.
The signal is then applied to a simulated DUT that generates AM/AM and AM/PM distortion.
To perform the measurement, proceed as follows:
1.
Open one or more result displays ( button).
In its default state, the result display shows the Power aspect in combination with
the Standard evaluation method.
There is no limit to the number of result display you can open simultaneously.
2.
Press the
button in the toolbar to start the measurement.
R&S FS-K130PC performs a single measurement. It shows the results in the form
of a trace in the diagram of the result display.
3.
Press the
button in the toolbar again to open a second result display window.
Depending on the screen layout, R&S FS-K130PC either opens the result display
in a second window or adds a tab to the result display you have already open. If in
a tab, drag the result display out of the tab and dock it somewhere else to view
both result displays at the same time.
4. Configure the result display(s) as you wish.
After running the measurement, you can configure the result display. For more
information see chapter 5, "Analyzing Measurement Results", on page 115.
You can also run a measurement without opening a result display window first (graphical or numerical).
SCPI command:
Initiate a measurement: INIT:IMM
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Configuring Instruments
Check if ready (query only): INIT:BUSY?
4.1.1 Controlling the Measurement
You can perform a measurement and control the course of the measurement.
●
starts the measurement. A measurement consists of capturing the data and dis-
playing the results.
By default, the R&S FS-K130PC performs one measurement after you press the
button; that means the R&S FS-K130PC fills its capture buffer once and shows the
results to the data in the capture buffer.
●
pauses the measurement by interrupting the measurement without updating the
result display. If you are measuring continuously, it interrupts the measurement
loop. The result display shows the results to the last successfully finished measurement.
●
starts a continuous measurement. After each update of the result display, a new
measurement begins.
●
reruns the measurement. Compared to a single measurement ( ), the software
does not capture new data before updating the result display. Instead it uses the
same data and calculates the results again (e.g. based on a change in the DSP
settings).
4.2 Configuring Instruments
If you have any hardware component in the test setup (like an analyzer or generator),
define the characteristics of the remote connection in the "Instrument Configuration"
dialog box.
►
Click on the button or select the "Instrument Connection" menu item from the
"File" menu.
The "Instrument Connection Configuration" dialog box opens.
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Instrument Assignment
The table shows all available instruments including their IDs, if you have queried them.
You can always check if the instrument is connected by clicking on the "Check all
Instrument Connections" button.
If there is more than one anaalyzer or generator in the list, the software automatically
uses the first of the instruments it can find.
Selected Instrument
You can configure one of the instruments in the list by selecting it. The details of the
instrument connections are then shown in the "Selected Instrument" area of the dialog
box.
You now can:
●
define the address of the instrument.
●
see the resulting VISA String
●
check the instrument status and test the selected instrument connection.
4.3 Configuring the Measurement
The Hardware Configuration window serves several purposes. For one, it visualizes
the data flow in a block diagram. The block diagram consists of all hardware components you're using in the measurement. In addition, you define settings via the hardware configuration.
► Select the "Hardware Configuration" menu item from the "Windows" menu.
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Configuring the Measurement
The "Instrument Connection Configuration" dialog box opens.
This chapter contains a detailed description of all elements and settings available in
the "Hardware Configuration" dialog box.
● Configuring the I/Q Generation............................................................................... 59
● Converting the Baseband Signal.............................................................................70
● Attenuating at the DUT Input...................................................................................74
● Configuring the DUT............................................................................................... 75
● Defining Signal Models........................................................................................... 81
● Attenuating the DUT Output....................................................................................85
● Converting the RF Signal........................................................................................86
● Configuring the I/Q Recorder.................................................................................. 89
4.3.1 Configuring the I/Q Generation
The "I/Q Generator" component generates the I/Q reference signal or input data for the
DUT to work with. The dialog box contains all parameters related to the baseband signal like signal type or signal parameters.
The I/Q Generator component corresponds to the ARB of a signal generator or a
stand-alone ARB (like the R&S AMU).
► Click on the "I/Q Generator" component in the "Hardware Configuration" element.
The "I/Q Generator Properties" dialog box opens.
● Usage......................................................................................................................60
● Main Settings.......................................................................................................... 60
● Configuring the Internal Stimulus............................................................................62
● Configuring a Noise Stimulus..................................................................................63
● Configuring a Dual Tone Stimulus.......................................................................... 65
● Configuring the Digital Modulation.......................................................................... 65
● Configuring a Pulse Stimulus..................................................................................66
● Configuring a File Stimulus..................................................................................... 67
● Controlling Markers.................................................................................................68
● Hardware Information..............................................................................................69
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4.3.1.1 Usage
Contains basic settings for the signal generator.
ARB Available for Control............................................................................................. 60
Reset ARB at Start........................................................................................................60
ARB Available for Control
Turns control of the signal generator on and off.
When you turn generator control on, the software applies the configuration as defined
in the "I/Q Generator" properties (via remote control).
Turning generator control off, implicates that you have to configure the generator manually.
Remote command:
CONF:IQGEN:REM:ENAB
Reset ARB at Start
Turns an automatic reset of the signal generator prior to a measurement on and off.
When you turn the reset on, the software applies the configuration you have defined for
the signal generator each time a measurement starts.
Remote command:
CONF:IQGEN:REM:PRES
4.3.1.2 Main Settings
Contains general characteristics of the signal generator.
ARB Upload Behavior................................................................................................... 60
I/Q Reference Signal Type............................................................................................61
ARB Root File Name.....................................................................................................61
Link Clock to System Bandwidth...................................................................................61
ARB Upload Behavior
Selects the condition of when to initiate a signal upload.
The upload may take a while, depending on the number of I/Q samples. The number of
samples can reach 1.000.000.
An upload is only necessary if the signal has been changed. Therefore you can set up
the R&S FS-K130PC to check the signal and upload the waveform only if it has been
changed.
●
"Always"
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Uploads the signal even if the content is identical to the old one.
●
"On Changed Data"
Uploads the signal only if it has been changed.
●
"Never (Offline)"
Never uploads the signal.
Remote command:
CONF:IQGEN:MAIN:LOAD NEVER | ONCHANGE | ALWAYS
I/Q Reference Signal Type
Selects the type and origin of the reference signal.
R&S FS-K130PC supports measurements on nearly any type of signal.
Two signal types are already provided. In addition, it supports the use of customized
reference signals.
●
"Noise"
Generates a noise signal using multi-carrier technique with constant carrier level
and random carrier phases, trimming the phase to match the selected crest factor.
●
"Dual Tone"
Generates a two-tone signal with random phase and defined spacing.
●
"Digital Modulated"
Generates a digital modulated signal.
●
"File"
Imports the signal from a file that contains the signal characteristics. You can
choose from various file formats.
●
"Pre-recorder Reference Signal"
Uses a signal that has been previously measured and taken from the analyzer
while performing a reference measurement.
●
"Signal Running on the ARB Generator"
Uses a signal from an ARB file that you have created on a signal generator.
Note that it is not possible to export I/Q data if you use this type of reference signal.
For more information see
●
chapter 4.3.1.8, "Configuring a File Stimulus", on page 67
●
chapter 4.5, "Specifying the File Type", on page 107
Remote command:
CONF:IQGEN:MAIN:SIG
NOISE | DTONE | DMOD | FILE | PREC | ARBWV
ARB Root File Name
Defines a file name prefix for any files that are transferred from the ARB generator.
You can specify different file name prefixes for each measurement. The file name is
completed depending on its contents, e.g. _ORIG in case of the reference signal.
Remote command:
CONF:IQGEN:MAIN:NAME 'string'
Link Clock to System Bandwidth
Couples or decouples the generator clock rate to the system bandwidth.
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If you decouple the generator clock rate from the system bandwidth, you can use signals with a low clock rate and measure them with a higher sampling rate. This allows
you to measure nonlinear effects correctly.
For more information see
●
"Manual Generator Clock Rate / Resulting Generator Clock Rate" on page 63
●
"System Bandwidth" on page 89
Remote command:
CONF:IQGEN:MAIN:LINK ON | OFF
4.3.1.3 Configuring the Internal Stimulus
Defines the characteristics of the internal stimulus.
Number of Samples...................................................................................................... 62
Random Seed............................................................................................................... 62
Manual Generator Clock Rate / Resulting Generator Clock Rate.................................63
Number of Samples
Defines the number of samples that the test signal consists of.
A number that is a power of 2 will speed up the internal signal processing. Thus, such
a number should be specified if no other requirements limit the choice of the sample
count.
Note: Defining the number of samples is necessary only if the reference signal type is
"Noise" or "Dual Tone". Defining the number of samples is also necessary for the reference signal measurement mode.
For more information see "Duty Cycle" on page 67.
Remote command:
CONF:IQGEN:INT:SAMP <numeric value>
Random Seed
Defines the value for the random seed that initializes the random generator used during the internal signal generation process.
Any number you enter here generates a different phase distribution and, therefore, a
different signal. Values ≥ 0 result in a generation of the same distribution in every measurement. A value of -1 results in the generation of a different distribution in every
measurement.
Note: The random seed works only with "Noise" and "Dual Tone" signals.
You can use the random seed, for example, to initialize the multi carrier phases of a
noise signal.
Remote command:
CONF:IQGEN:INT:SEED <numeric value>
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Manual Generator Clock Rate / Resulting Generator Clock Rate
Defines the clock rate the I/Q source generates the signal with.
You can either set the generator clock rate manually or couple the generator clock rate
to the system bandwidth. In that case, the software shows the resulting generator clock
rate in the corresponding field.
For more information see
●
"System Bandwidth" on page 89
●
"Link Clock to System Bandwidth" on page 61
Note that if the generator clock rate is different from the system bandwidth, the
R&S FS-K130PC runs a resampling.
The purpose of the R&S FS-K130PC is to measure nonlinear effects. These generate
spectral regrowth (amplitude components in addition to the signal). Therefore you need
to select a sampling rate (or recording bandwidth) in order to be able to record the signal and nonlinear effects.
Note: If you generate the signal with a file that already contains clock rate information,
R&S FS-K130PC uses the clock rate specified here instead of that specified in the file.
Remote command:
Manual clock rate: CONF:IQGEN:INT:CLOCK <numeric value>
Clock rate coupled to system bandwidth (query only): CONF:IQGEN:INT:GENC?
4.3.1.4 Configuring a Noise Stimulus
Defines the characteristics of a noise reference signal.
Generator Bandwidth.................................................................................................... 63
Crest Factor.................................................................................................................. 64
Noise Notch Width........................................................................................................ 64
Noise Notch Offset........................................................................................................ 64
Initial Search Cycles......................................................................................................64
Adjustment Cycles........................................................................................................ 64
Adjustment Steps.......................................................................................................... 65
Maximum Error..............................................................................................................65
Generator Bandwidth
Defines the bandwidth of an internally generated noise reference signal.
If you have selected a "Noise" reference signal, enter the RF bandwidth of the signal.
For more information see
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●
"I/Q Reference Signal Type" on page 61
Remote command:
CONF:IQGEN:NOISE:BW <numeric value>
Crest Factor
Defines the crest factor for the signal.
The crest factor shows the average power in relation to the peak power.
Remote command:
CONF:IQGEN:NOISE:CREST <numeric value>
Noise Notch Width
Defines the width of a notch that you can add to a noise signal.
Within the notch, all carriers of the noise signal have zero amplitude. You can use the
noise notch to, for example, determine the noise power ratio (NPR) before and after
the DPD.
Remote command:
CONF:IQGEN:NOISE:NOTCH:WIDTH <numeric value>
Noise Notch Offset
Defines an offset for the noise notch.
The offset moves the noise notch to a position outside the center of the signal. You can
use the offset to, for example, generate a one-sided noise signal or to examine asymmetric distortion effects.
Remote command:
CONF:IQGEN:NOISE:NOTCH:OFFS <numeric value>
Initial Search Cycles
Defines the number of cycles that are performed during the initial search for the signal
with a crest factor closest to the one you have defined.
To find the signal with the best crest factor, the software performs an initial signal
search. The initial search is an algorithm that uses pure random phase distributions
with different initial seed values. When the number of search cycles has been completed, the R&S FS-K130PC uses the signal that resembles most the crest factor you
have defined and uses that signal for further optimization of the crest factor.
Remote command:
CONF:IQGEN:NOISE:ICYC <numeric value>
Adjustment Cycles
Defines the number of test cycles to determine the signal with the crest factor closest
to the one you have defined.
The adjustment cycles begin after the initial search has been done.
For more information see "Initial Search Cycles" on page 64.
Remote command:
CONF:IQGEN:NOISE:ACYC <numeric value>
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Adjustment Steps
Defines the number of different signal combinations used during one (crest factor)
adjustment cycle.
Remote command:
CONF:IQGEN:NOISE:ASTEP <numeric value>
Maximum Error
Defines the maximum error tolerable for crest factor optimization.
If the difference between the crest factor you have defined and the best crest factor
that has been found during the search is bigger than the maximum error you have
defined, the R&S FS-K130PC aborts the crest factor optimization.
Remote command:
CONF:IQGEN:NOISE:MAXERR <numeric value>
4.3.1.5 Configuring a Dual Tone Stimulus
Defines the characteristics of a dual tone reference signal.
Tone Spacing................................................................................................................ 65
Tone Spacing
Defines the bandwidth of an internally generated dual tone reference signal.
If you have selected a "Dual Tone" reference signal, enter the spacing of the two
tones. If you enter, e.g., 1 MHz, R&S FS-K130PC generates two tones, one at
+500 kHz and one at -500 kHz.
For more information see
●
"I/Q Reference Signal Type" on page 61
Remote command:
CONF:IQGEN:DUAL:SPAC <numeric value>
4.3.1.6 Configuring the Digital Modulation
Defines the modulation characteristics of a digitally modulated reference signal.
Modulation Type............................................................................................................66
Number of Symbols.......................................................................................................66
Oversampling................................................................................................................ 66
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Filter Type..................................................................................................................... 66
Filter Roll-Off................................................................................................................. 66
Symbol Rate..................................................................................................................66
Modulation Type
Selects the modulation for a digitally modulated stimulus.
Remote command:
CONF:IQGEN:DMOD:TYPE QPSK | OQPSK | 8PSK | 3PI_8_8PSK | 16QAM |
32QAM
Number of Symbols
Defines the number of symbols that a digitally modulated signal contains.
If you want to generate a 3pi/8-8PSK modulated signal, the number of symbols has to
be an integer multiple of 16.
Remote command:
CONF:IQGEN:DMOD:SYMB <numeric value>
Oversampling
Defines an oversampling factor for digitally modulated signals.
Oversampling decreases the occupied bandwidth of a signal by increasing the signal
clock rate.
For DPD measurements, you should use an oversampling factor of 4 or more.
Remote command:
CONF:IQGEN:DMOD:OV <numeric value>
Filter Type
Selects the pulse shaping filter type for digital modulation.
Remote command:
CONF:IQGEN:DMOD:FILT RRC | RC
Filter Roll-Off
Defines the roll-off factor for the digital modulation filter.
The roll-off factor defines the shape of the filter slopes.
Remote command:
CONF:IQGEN:DMOD:ROLL <numeric value>
Symbol Rate
Shows the symbol rate of digitally modulated signals. The symbol rate is the ratio of
the clock rate and the oversampling.
Remote command:
CONF:IQGEN:DMOD:SRAT <numeric value>
4.3.1.7 Configuring a Pulse Stimulus
Defines the characteristics of a pulsed reference signal.
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Note that pulse stimulus settings are automatically used if the reference signal is
pulsed and its information is contained in a file.
Duty Cycle.....................................................................................................................67
Ramp Length.................................................................................................................67
Duty Cycle
Defines the duty cycle of a pulsed signal.
The duty cycle of a pulse is the ratio of the pulse duration and the actual length of the
pulse.
Example:
The pulse duration is 2 µs. The actual length of the pulse is 1 µs. The duty cycle is
1 µs:2 µs = 0.5 or 50%.
Remote command:
CONF:IQGEN:PULS:DUTY <numeric value>
Ramp Length
Defines the number of samples that are included on each side of the pulse to increase
or reduce the power to zero.
Within this range, the signal is repeated and the pulse shaping filter (a cosine filter) is
applied.
Remote command:
CONF:IQGEN:PULS:RAMP <numeric value>
4.3.1.8 Configuring a File Stimulus
Defines the characteristics of a file that contains the reference signal.
For more information see chapter 4.5, "Specifying the File Type", on page 107.
File Type....................................................................................................................... 67
Stimulus and Response File Name...............................................................................68
Stimulus and Response File Name (Secondary File)................................................... 68
File Type
Opens the "Data File Format Definition" dialog box to import various standard signal
type or generic I and Q data files.
The "Data File Format Definition" dialog box contains functionality to define the file format in case you are using reference signal information from a file.
For more information see
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●
chapter 4.5, "Specifying the File Type", on page 107
Remote command:
I/Q Generator: CONF:IQGEN:FILE:TYPE <TYPE>
I/Q Recorder: CONF:IQSINK:FILE:TYPE <TYPE>
<TYPE>: BIN1 | BIN2 | ASC1 | ASC2 | MAT | M | IQW | IBN | WV |
FSX | SIM | DSUIT
Stimulus and Response File Name
Selects the file that contains the reference or measurement signal information.
Remote command:
I/Q Generator: CONF:IQGEN:FILE:NAME 'string'
I/Q Recorder: CONF:IQSINK:FILE:NAME 'string'
Stimulus and Response File Name (Secondary File)
Select a secondary file that contains the reference or measurement signal information.
Selecting a secondary file is necessary only if you use a file type that requires two files.
Remote command:
I/Q Generator: CONF:IQGEN:FILE:NAME2 'string'
I/Q Recorder: CONF:IQSINK:FILE:NAME2 'string'
4.3.1.9 Controlling Markers
Defines marker characteristics.
Restart Marker.............................................................................................................. 68
Marker 1/2/3/4 Offset.................................................................................................... 68
Restart Marker
Selects the marker you want to use as the restart marker.
The restart marker is generated by the ARB generator as TTL level signal at the
marker output port. The restart marker is positioned on HIGH at the waveform start
(sample index 0) and on LOW after half of the waveform length.
Remote command:
CONF:IQGEN:MARK:REST MARK1 | MARK2 | MARK3 | MARK4
Marker 1/2/3/4 Offset
Specifies the marker offset relative to the start of the waveform (sample index 0).
R&S FS-K130PC ignores a marker offset if the marker is also the restart marker.
Note: You can define a negative marker offset. A negative offset results in a pre-trigger
that positions the marker on HIGH prior to the waveform start.
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The length of the HIGH period is 1/100 of the waveform length if there are more then
1000 samples and ½ of the waveform length if there are less then 1000 samples.
Remote command:
CONF:IQGEN:MARK<x>:OFFS <numeric value>
with <x> being a number from 1 to 4.
4.3.1.10 Hardware Information
Shows information about the hardware in use.
VISA Instrument Address..............................................................................................69
Instrument Type............................................................................................................ 69
Instrument Type............................................................................................................ 69
Instrument Options........................................................................................................70
VISA Instrument Address
Shows the VISA address of the instrument currently in use.
For more information see.
●
chapter 4.2, "Configuring Instruments", on page 57
Remote command:
I/Q Generator: CONF:IQGEN:HW:VISA 'string'
Input Mixer: CONF:UPCO:HW:VISA 'string'
Ouput Mixer: CONF:DOCO:HW:VISA 'string'
Instrument Type
Shows name, serial number and firmware version of the instrument currently in use.
This corresponds to the response to the *IDN command supported by external equipment.
Remote command:
I/Q Generator (query only): CONF:IQGEN:HW:IDN?
Input Mixer (query only): CONF:UPCO:HW:IDN?
Output Mixer (query only): CONF:DOCO:HW:IDN?
Instrument Type
Shows the type of instrument that has been detected.
The instrument type is found out via the instrument IDN. If the instrument is not detected as a Rohde & Schwarz instrument, "unknown" is displayed.
Remote command:
I/Q Generator (query only): CONF:IQGEN:HW:TYPE?
Input Mixer (query only): CONF:UPCO:HW:TYPE?
Output Mixer (query only): CONF:DOCO:HW:TYPE?
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Instrument Options
Shows the options that are installed on the instrument currently in use.
This corresponds to the response to the *OPT command supported by external equipment.
Remote command:
I/Q Generator (query only): CONF:IQGEN:HW:OPT?
Input Mixer (query only): CONF:UPCO:HW:OPT?
Output Mixer (query only): CONF:DOCO:HW:OPT?
4.3.2 Converting the Baseband Signal
A true RF DUT needs a baseband signal converted into an RF signal. The corresponding component is the RF section of a vector signal generator or a separate I/Q to RF
converter. All settings necessary for the up-conversion are available through the "Input
Mixer" dialog box.
► Click on the "Input Mixer" component in the "Hardware Configuration" element.
The "Input Mixer Properties" dialog box opens.
● Usage......................................................................................................................70
● Main Settings.......................................................................................................... 71
● Configuring a Digital IF Shift................................................................................... 72
● Standalone Options.................................................................................................72
● Hardware Information..............................................................................................73
● Special Options.......................................................................................................74
4.3.2.1 Usage
Contains basic settings for the input mixer.
Input Mixer Available for Control................................................................................... 70
Reset Input Mixer at Start............................................................................................. 71
Control Power............................................................................................................... 71
Input Mixer Available for Control
Turns control of the input mixer on and off.
When you turn input mixer control on, the software applies the configuration as defined
in the "Input Mixer" properties (via remote control).
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Turning input mixer control off, implicates that you have to configure the input mixer
manually.
Remote command:
CONF:UPCO:REM:ENAB
Reset Input Mixer at Start
Turns an automatic reset of the input mixer prior to a measurement on and off.
When you turn the reset on, the software applies the configuration you have defined for
the input mixer each time a measurement starts.
Remote command:
CONF:UPCO:REM:PRES
Control Power
Turns control of the input power on and off.
When you turn the power control off, the software also turns off the auto leveling mechanism and uses the power level you have defined manually instead.
Remote command:
CONF:UPCO:REM:POW
4.3.2.2 Main Settings
Contains general characteristics of the input mixer.
RF Frequency............................................................................................................... 71
RF Output Path............................................................................................................. 71
BB Output Path............................................................................................................. 72
Settling Delay................................................................................................................ 72
RF Frequency
Shows the frequency at the DUT input.
Note that this field is read only. R&S FS-K130PC calculates the frequency from the
DUT properties.
Remote command:
Query only:
CONF:UPCO:FREQ?
RF Output Path
Selects the RF path if more than one is available on the signal generator in use.
Remote command:
CONF:UPCO:PATH:RF A | B
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BB Output Path
Selects the baseband output path if more than one is available on the signal generator
in use.
Remote command:
CONF:UPCO:PATH:BB A | B | SMIQ
Settling Delay
Defines the time the DUT needs to settle after you have changed a input parameter or
have started a measurement.
Any DUT usually has its characteristics settling time. Thus, it is necessary to wait until
the DUT has settled after you have changed one of the DUT input parameters and
before you can perform further measurements on the DUT output.
Remote command:
CONF:UPCO:SETTL <numeric value>
4.3.2.3 Configuring a Digital IF Shift
Defines the characteristics of a digital IF shift.
Digital IF Shift................................................................................................................72
IF Frequency................................................................................................................. 72
Digital IF Shift
Turns the digital IF shift on and off.
Shifting the IF is a method to eliminate interfering signals. The passband remains the
same when you shift the frequency.
The IF shift is implemented digitally.
Remote command:
CONF:UPCO:IF:MODE OFF | INWV | INHW
IF Frequency
Defines the intermediate frequency to generate the baseband I/Q signal with.
Generating a baseband I/Q signal may be required to, for example, move the baseband signal out of the range of influence of the (unwanted) generator DC component.
Note: Make sure to compensate an IF shift in the baseband generation. To compensate the IF shift, apply a corresponding frequency offset in the DUT configuration. The
offset sets the measurement frequency of the analyzer to the correct frequency.
Remote command:
CONF:UPCO:IF:FREQ <numeric value>
4.3.2.4 Standalone Options
Contain miscellaneous options and parameters for the input mixer.
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Signal Generator PEP Level......................................................................................... 73
Signal Generator PEP Level
Defines the peak envelope power (PEP) level of the signal generator.
Remote command:
CONF:UPCO:SGEN:PEP <numeric value>
4.3.2.5 Hardware Information
Shows information about the hardware in use.
VISA Instrument Address..............................................................................................73
Instrument Type............................................................................................................ 73
Instrument Type............................................................................................................ 73
Instrument Options........................................................................................................74
VISA Instrument Address
Shows the VISA address of the instrument currently in use.
For more information see.
●
chapter 4.2, "Configuring Instruments", on page 57
Remote command:
I/Q Generator: CONF:IQGEN:HW:VISA 'string'
Input Mixer: CONF:UPCO:HW:VISA 'string'
Ouput Mixer: CONF:DOCO:HW:VISA 'string'
Instrument Type
Shows name, serial number and firmware version of the instrument currently in use.
This corresponds to the response to the *IDN command supported by external equipment.
Remote command:
I/Q Generator (query only): CONF:IQGEN:HW:IDN?
Input Mixer (query only): CONF:UPCO:HW:IDN?
Output Mixer (query only): CONF:DOCO:HW:IDN?
Instrument Type
Shows the type of instrument that has been detected.
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The instrument type is found out via the instrument IDN. If the instrument is not detected as a Rohde & Schwarz instrument, "unknown" is displayed.
Remote command:
I/Q Generator (query only): CONF:IQGEN:HW:TYPE?
Input Mixer (query only): CONF:UPCO:HW:TYPE?
Output Mixer (query only): CONF:DOCO:HW:TYPE?
Instrument Options
Shows the options that are installed on the instrument currently in use.
This corresponds to the response to the *OPT command supported by external equipment.
Remote command:
I/Q Generator (query only): CONF:IQGEN:HW:OPT?
Input Mixer (query only): CONF:UPCO:HW:OPT?
Output Mixer (query only): CONF:DOCO:HW:OPT?
4.3.2.6 Special Options
Contains various special parameters to configure the input mixer with.
Post-Config Commands................................................................................................ 74
Post-Config Commands
Opens a dialog box to define remote control commands that should be processed after
the generator has been configured and the waveform data has been loaded.
In the dialog box, you can enter an array of remote commands, one per line. These
commands will be sent to the generator in addition to the parameters that you can configure in the R&S FS-K130PC.
Remote command:
CONF:UPCO:CONF:POST <string>
4.3.3 Attenuating at the DUT Input
It may be necessary to attenuate the signal at the DUT input because of DUT restrictions and to avoid damage to the DUT.
Specifying the input attenuation also helps to display correct values in the measurement report and to run the model calculation on real measurement values.
► Click on the "DUT Input Attenuation" component in the "Hardware Configuration"
element.
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The "DUT Input Attenuation Properties" dialog box opens.
● Main Settings.......................................................................................................... 75
4.3.3.1 Main Settings
Contains general characteristics of the DUT input.
Fixed Attenuation.......................................................................................................... 75
Fixed Attenuation
Defines the attenuation at the DUT input or output in dB.
Remote command:
Input attenuation: CONF:IATT:FIX <numeric value>
Output attenuation: CONF:OATT:FIX <numeric value>
4.3.4 Configuring the DUT
The DUT Properties dialog box contains parameters to characterize the DUT you are
going to test.
► Click on the "DUT" component in the "Hardware Configuration" element.
The "DUT Properties" dialog box opens.
● Main Settings.......................................................................................................... 75
● Test Settings........................................................................................................... 76
● Maximum DUT Input Ratings..................................................................................77
● Frequency Conversion Configuration......................................................................78
● Auto Leveling.......................................................................................................... 79
4.3.4.1 Main Settings
Contains general characteristics of the DUT.
Input Port Type..............................................................................................................75
Output Port Type...........................................................................................................76
Input Port Type
Selects the port type at the DUT input.
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You can choose from various port types like RF, baseband or digital inputs with different standards of interconnection (impedance, …).
Currently only the RF input port is supported.
Remote command:
CONF:DUT:INP:PORT RF
Output Port Type
Selects the port type at the DUT output.
You can choose from various port types like RF, baseband or digital inputs with different standards of interconnection (impedance, …).
Currently only the RF input port is supported.
Remote command:
CONF:DUT:OUTP:PORT RF
4.3.4.2 Test Settings
Contains general characteristics of the test setup.
DUT Output RMS Level................................................................................................ 76
DUT Output Frequency................................................................................................. 76
Input Frequency............................................................................................................ 76
Post-Measurement Generator Level............................................................................. 77
Generator Stand-by Level............................................................................................. 77
DUT Output RMS Level
Defines the RMS level at the DUT output.
The RMS level is the output power level the R&S FS-K130PC performs the measurement with.
Remote command:
CONF:DUT:OUT:RMS <numeric value>
DUT Output Frequency
Defines the frequency at the DUT output.
The measurement frequency is the frequency the R&S FS-K130PC performs the measurement on.
Remote command:
CONF:DUT:OUT:FREQ <numeric value>
alternatively: FREQ:CENT <numeric value>
Input Frequency
Calculates and shows the input frequency of the DUT.
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The input frequency depends on the output frequency and the Frequency Conversion
Configuration. It is calculated according to the following formula:
fin=(f
-FrequencyOffset)*
out
divider
/
multiplier
Remote command:
Query only: CONF:DUT:INP:FREQ? <numeric value>
Post-Measurement Generator Level
Selects the method of level configuration at the end of the measurement.
In some test setups (e.g. due to thermal restrictions), it may be necessary to reduce
the DUT input power after the measurement. The available generator behaviors are as
follows:
●
"Leave In Last Level Config"
Maintains the level of the last measurement.
●
"Power to Stand-by"
Adjusts the level after the measurement according to the Generator Stand-by
Level.
●
"Switch Off"
Deactivates the generator RF output after the measurement.
Remote command:
CONF:DUT:POST:MODE LEAVE | STANDBY | OFF
Generator Stand-by Level
Defines the maximum power level of the signal generator after the measurement is
done.
Note that the generator stand-by level is relevant only if you have set the Post-Mea-
surement Generator Level accordingly.
Remote command:
CONF:DUT:POST:LEV <numeric value>
4.3.4.3 Maximum DUT Input Ratings
Defines the level characteristics at the DUT input.
Maximum Peak Level....................................................................................................77
Maximum RMS Level.................................................................................................... 78
Maximum Peak Level
Defines the maximum peak power level allowed at the DUT input.
In order to avoid damage to the DUT, you can define the maximum peak power level
that is allowed at the DUT input. The value you enter here is also considered during
the auto level procedure.
Remote command:
CONF:DUT:MAX:PEAK <numeric value>
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Maximum RMS Level
Defines the maximum RMS power level allowed at the DUT input.
In order to avoid damage to the DUT, you can define the maximum RMS power level
that is allowed at the DUT input. The value you enter here is also considered during
the auto level procedure.
Remote command:
CONF:DUT:MAX:RMS <numeric value>
4.3.4.4 Frequency Conversion Configuration
Defines characteristics of frequency converting DUTs.
The DUT output frequency depends on the input frequency, the multiplier, the divider
and the frequency offset.
For more information on how you can calculate the output frequency see "Input Fre-
quency" on page 76.
Multiplier........................................................................................................................78
Divider........................................................................................................................... 78
Frequency Offset...........................................................................................................78
Multiplier
Defines the frequency multiplication factor for a frequency converting DUT.
For more information on how the multiplier is used see "Input Frequency" on page 76.
Remote command:
CONF:DUT:FCON:MUL <numeric value>
Divider
Defines a frequency division factor for a frequency converting DUT.
For more information on how the divider is used see "Input Frequency" on page 76.
Remote command:
CONF:DUT:FCON:DIV <numeric value>
Frequency Offset
Defines the frequency offset for a frequency converting DUT.
For more information on how the frequency offset is used see "Input Frequency"
on page 76.
Remote command:
CONF:DUT:FCON:OFFS <numeric value>
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4.3.4.5 Auto Leveling
Defines the characteristics of the auto level routine.
The R&S FS-K130PC automatically sets the level at the DUT output by performing an
auto level routine.
Turning off auto leveling
Note that you can turn off auto leveling by turning off Control Power.
Usually you do not have to modify any auto leveling settings to get correct results.
Some DUTs however have special characteristics and the software needs to be set up
accordingly.
The auto level routine works as follows:
●
Raw leveling
The process begins with an initial power level. This initial level is the sum of
DUT Level - Max Gain - Initial Power Reduction
The software then increases or decreases the power level in even steps until it is
close to the requested output level. The software uses the difference to the requested power level as a correction value.
●
Fine leveling
When the level comes close to the requested level, the steps are adjusted according to the difference in requested and configured level until the level comes even
closer to the requested level.
The difference between the DUT level and the
If the maximum number of leveling steps is reached without coming close enough
to the requested level, the process is terminated with an error.
Learn Gain Curve..........................................................................................................79
Initial Power Reduction................................................................................................. 80
Leveling Cycles............................................................................................................. 80
Maximum Level Error.................................................................................................... 80
Raw Adjust Step Size....................................................................................................80
Auto Leveling Domain................................................................................................... 80
Maximum Number of Samples......................................................................................81
Learn Gain Curve
Turns an algorithm that remembers past gain curves on and off and includes those in
the auto leveling process.
Remote command:
CONF:DUT:ALEV:LEARN ON | OFF
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Initial Power Reduction
Defines the power reduction of the DUT.
The power reduction is part of the calculation of the initial power of the auto level process.
If you don't know the exact reduction of the DUT you have to enter an approximate
value or the reduction that you expect.
Remote command:
CONF:DUT:ALEV:PRED <numeric value>
Leveling Cycles
Defines the maximum number of auto-leveling loops that are performed until the autolevel routine stops.
The leveling process may – due to special DUT effects like a negative gradient gain
curve or heavy nonlinear effects – end up in an endless loop. The number you enter
here defines the maximum number of auto-leveling attempts until R&S FS-K130PC
aborts the levelling process.
By setting the maximum number of level loops, you can avoid dead-lock loops on
amplifiers with a massive non-linear characteristic.
The number of level loops is the counter during both stages (raw and fine leveling) of
the auto level process.
Remote command:
CONF:DUT:ALEV:CYC <numeric value>
Maximum Level Error
Defines the maximum tolerable level difference between measured and requested output power of the DUT.
R&S FS-K130PC uses the level error to check if the leveling process can be completed
successfully.
Remote command:
CONF:DUT:ALEV:MAXERR <numeric value>
Raw Adjust Step Size
Defines the step size of the generator output power used for the approximation of the
output level of the DUT.
Remote command:
CONF:DUT:ALEV:STEP <numeric value>
Auto Leveling Domain
Selects the type of measurement that the R&S FS-K130PC uses for the auto-leveling
process.
●
"Time Domain Power Measurement"
Performs the auto level procedure in the time domain (zero span) of the analyzer.
●
"Based on I/Q Data"
Performs the auto level procedure on I/Q data.
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By default, the R&S FS-K130PC performs the auto-level process in the time domain as
it is much faster compared to measurements on I/Q data, especially if you have long
I/Q data sets.
Remote command:
CONF:DUT:ALEV:DOM IQ | TDOM
Maximum Number of Samples
Defines the maximum number of I/Q samples to capture during the auto-level process.
If you have a very large I/Q data set as reference signal, capturing I/Q data for autoleveling purpose can take a long time.
If you perform the auto level procedure based on I/Q data, you can set a maximum
sample count that is used if the complete sample exceeds the value you have entered
here.
For more information see
●
"Auto Leveling Domain" on page 80
Remote command:
CONF:DUT:ALEV:IQSAM <numeric value>
4.3.5 Defining Signal Models
The "Simulation" component generates a simulated signal that you can use instead of
the hardware. The dialog box contains settings to characterize such a signal.
► Click on the "Simulation" component in the "Hardware Configuration" element.
The "Simulation" dialog box opens.
● Selecting the Data Source...................................................................................... 81
● Defining a Signal Model.......................................................................................... 82
● Including Noise........................................................................................................83
● Defining Signal Impairments................................................................................... 84
4.3.5.1 Selecting the Data Source
Selects the data source.
Measurement Data Source........................................................................................... 81
Measurement Data Source
Selects the source of the I/Q data.
You can get the measurement data at the DUT output in three ways:
●
"Hardware"
Data recording by measuring the data with an analyzer
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●
"File"
Import the data you want to measure via a file
●
"Internal simulation"
Simulate a DUT according to specification.
Remote command:
CONF:IQSINK:SOUR HW | FILE | SIM
Configuring the Measurement
4.3.5.2 Defining a Signal Model
Defines the characteristics of the signal model.
Apply Model.................................................................................................................. 82
Model............................................................................................................................ 82
Premodel Gain.............................................................................................................. 83
Postmodel Gain.............................................................................................................83
Use Model For DPD...................................................................................................... 83
Apply Model
Turns the nonlinearity model in the DUT simulation on and off.
Remote command:
CONF:DUT:SIM:MOD:STAT ON | OFF
Model
Opens a dialog box to select and define the simulation curve.
The software already provides several predefined simulation curves that you can select
from the "Predefined Model" dropdown menu. The graphical representation of the
model with the corresponding output spectrum is also part of the dialog box.
When you right-click on the diagrams, the corresponding context menus provide functionality similar to that of the context menu for the result diagrams.
●
Hardcopy functionality
●
Zooming functionality
●
Scaling functionality
In the default state, the input peak for all models is 0 dBm. You can change the input
peak in steps of 1 dBm.
In the "File" menu of the Simulation Curve Editor, you can
●
restore the scaling of the diagrams
●
select the signal type (dual tone or noise)
Remote command:
CONF:DUT:SIM:MOD:MODEL LINEAR | DING2 | DING1 | DING4 | AGILENT
| DINGNOMEM | FILTER | GROB | KOKKELER | R4-081509 | R4-082544 |
TEST_001
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Premodel Gain
Defines the gain applied to the I/Q baseband signal before the software applies the
amplifier model.
Defining a premodel gain may be useful to, for example, move the amplifier model into
the saturation region without changing the input level.
Remote command:
CONF:DUT:SIM:MOD:PRE <numeric value>
Postmodel Gain
Defines the gain applied to the I/Q baseband signal after the software applies the
amplifier model.
Defining a postmodel gain may be useful to, for example, simulate a more linear gain
(and thus reduce nonlinear effects) without changing the input level.
Remote command:
CONF:DUT:SIM:MOD:POST <numeric value>
Use Model For DPD
Includes or excludes the DPD from the signal model.
When you turn it on, the software generates the signal at the DUT output with DPD by
feeding the DPD signal directly into the selected model.
Takes effect only if you simulate the signal.
Remote command:
CONF:DUT:SIM:MOD:MDPD ON | OFF
4.3.5.3 Including Noise
Defines characteristics of noise.
Apply Noise................................................................................................................... 83
Noise Seed....................................................................................................................83
S/N Ratio.......................................................................................................................84
Apply Noise
Turns noise in the DUT simulation on and off.
Remote command:
CONF:DUT:SIM:NOIS:STAT ON | OFF
Noise Seed
Defines the value for the random sequence generator that simulates noise.
Remote command:
CONF:DUT:SIM:NOIS:SEED <numeric value>
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S/N Ratio
Defines a signal-to-noise ratio for the simulated signal.
The S/N ratio is the noise power in relation to the main signal power. The lower the S/N
ratio, the higher the noise power level.
Remote command:
CONF:DUT:SIM:NOIS:SNR <numeric value>
4.3.5.4 Defining Signal Impairments
Contains various impairments applied to the signal.
Apply Impairments........................................................................................................ 84
Integer Timing Shift....................................................................................................... 84
Frequency Offset...........................................................................................................84
Phase Offset................................................................................................................. 84
I Offset...........................................................................................................................85
Q Offset.........................................................................................................................85
Gain Imbalance............................................................................................................. 85
Apply Impairments
Turns the impairments in the DUT simulation on and off.
Remote command:
CONF:DUT:SIM:IMP:STAT ON | OFF
Integer Timing Shift
Defines a timing shift for the simulated signal.
Remote command:
CONF:DUT:SIM:IMP:TIME <numeric value>
Frequency Offset
Defines a frequency offset that is added to the simulated signal.
Remote command:
CONF:DUT:SIM:IMP:FREQ <numeric value>
Phase Offset
Defines a phase offset that is added to the simulated signal.
Remote command:
CONF:DUT:SIM:IMP:PHA <numeric value>
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I Offset
Defines an offset for the I branch of the simulated signal.
Remote command:
CONF:DUT:SIM:IMP:IOFF <numeric value>
Q Offset
Defines an offset for the Q branch of the simulated signal.
Remote command:
CONF:DUT:SIM:IMP:QOFF <numeric value>
Gain Imbalance
Defines an I/Q gain imbalance for the simulated signal.
The gain imbalance is the difference of the gain in the I and Q branches.
Remote command:
CONF:DUT:SIM:IMP:GIMB <numeric value>
4.3.6 Attenuating the DUT Output
It may be necessary to attenuate the signal at the DUT output if the power level is very
high or due to analyzer restrictions. Attenuation of the signal can avoid damage to the
hardware.
In order to display correct power readings, the output attenuation value can be specified.
► Click on the "DUT Output Attenuation" component in the "Hardware Configuration"
element.
The "DUT Output Attenuation Properties" dialog box opens.
● Main Settings.......................................................................................................... 85
4.3.6.1 Main Settings
Contains general characteristics of the DUT input.
Fixed Attenuation.......................................................................................................... 85
Fixed Attenuation
Defines the attenuation at the DUT input or output in dB.
Remote command:
Input attenuation: CONF:IATT:FIX <numeric value>
Output attenuation: CONF:OATT:FIX <numeric value>
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4.3.7 Converting the RF Signal
When testing a DUT with an RF output you need to convert the RF signal back into a
baseband signal. The corresponding component is the RF section of a vector signal
analyzer. All settings necessary for the down-conversion are available through the
Down Converter dialog box.
► Click on the "Output Mixer" component in the "Hardware Configuration" element.
The "Output Mixer Properties" dialog box opens.
● Main Settings.......................................................................................................... 86
● Swapping and Inverting I/Q Data............................................................................ 87
● Hardware Information..............................................................................................87
4.3.7.1 Main Settings
Contains general characteristics of the input mixer.
RF Frequency............................................................................................................... 86
10 MHz Reference Frequency Source..........................................................................86
Use External Mixer........................................................................................................87
External Mixer Band......................................................................................................87
RF Frequency
Shows the frequency at the DUT output.
This is a read only field. R&S FS-K130PC automatically calculates the frequency from
the DUT properties.
For more information see
●
chapter 4.3.4.4, "Frequency Conversion Configuration", on page 78
Remote command:
Query only:
CONF:DOCO:FREQ?
10 MHz Reference Frequency Source
Defines the source of the reference frequency (10 MHz).
Use the reference frequency of the analyzer to get a better frequency accuracy. The
full synchronization can compensate the frequency error, but if possible, coupling the
reference frequencies is recommended.
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You can also supply an external frequency generator to be used as reference frequency (e.g. if the DUT generates its own reference frequency).
Remote command:
CONF:DOCO:REF OFF | IQGEN | INPMIX | OUTMIX | IQREC | EXT
Use External Mixer
Includes or excludes an external mixer from the test setup.
For more information on external mixers refer to the documentation of the product you
are using.
Remote command:
CONF:DOCO:MIX:STAT ON | OFF
External Mixer Band
Selects the frequency band of the external mixer.
If the external mixer you are using is in a frequency band other than the predefined
ones, you can also select a custom band ("User" menu item).
For more information on external mixers refer to the documentation of the product you
are using.
Remote command:
CONF:DOCO:MIX:BAND <numeric value>
4.3.7.2 Swapping and Inverting I/Q Data
Defines the handling of I/Q data.
Swap I/Q....................................................................................................................... 87
Invert I/Q....................................................................................................................... 87
Swap I/Q
Turns a swap of the inphase and quadrature parts of the signal on and off.
Remote command:
CONF:DOCO:IQ:SWAP ON | OFF
Invert I/Q
Inverts the inphase (I branch) and quadrature (Q branch) parts of the signal.
Remote command:
Invert I: CONF:DOCO:IQ:INVI ON | OFF
Invert Q: CONF:DOCO:IQ:INVQ ON | OFF
4.3.7.3 Hardware Information
Shows information about the hardware in use.
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VISA Instrument Address..............................................................................................88
Instrument Type............................................................................................................ 88
Instrument Type............................................................................................................ 88
Instrument Options........................................................................................................88
VISA Instrument Address
Shows the VISA address of the instrument currently in use.
For more information see.
●
chapter 4.2, "Configuring Instruments", on page 57
Remote command:
I/Q Generator: CONF:IQGEN:HW:VISA 'string'
Input Mixer: CONF:UPCO:HW:VISA 'string'
Ouput Mixer: CONF:DOCO:HW:VISA 'string'
Instrument Type
Shows name, serial number and firmware version of the instrument currently in use.
This corresponds to the response to the *IDN command supported by external equipment.
Remote command:
I/Q Generator (query only): CONF:IQGEN:HW:IDN?
Input Mixer (query only): CONF:UPCO:HW:IDN?
Output Mixer (query only): CONF:DOCO:HW:IDN?
Instrument Type
Shows the type of instrument that has been detected.
The instrument type is found out via the instrument IDN. If the instrument is not detected as a Rohde & Schwarz instrument, "unknown" is displayed.
Remote command:
I/Q Generator (query only): CONF:IQGEN:HW:TYPE?
Input Mixer (query only): CONF:UPCO:HW:TYPE?
Output Mixer (query only): CONF:DOCO:HW:TYPE?
Instrument Options
Shows the options that are installed on the instrument currently in use.
This corresponds to the response to the *OPT command supported by external equipment.
Remote command:
I/Q Generator (query only): CONF:IQGEN:HW:OPT?
Input Mixer (query only): CONF:UPCO:HW:OPT?
Output Mixer (query only): CONF:DOCO:HW:OPT?
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4.3.8 Configuring the I/Q Recorder
The last hardware component to configure is the I/Q analyzer. Like the I/Q generator, it
is part of every measurement configuration. The I/Q recorder measures the signal,
records the data at the DUT output and shows the results. Usually you will have a signal or spectrum analyzer as a data sink. The I/Q recording section of the analyzer is
the part that correponds to the I/Q Data Sink component.
► Click on the "I/Q Recorder" component in the "Hardware Configuration" element.
The "I/Q Generator Properties" dialog box opens.
● Main Settings.......................................................................................................... 89
● Response File Settings........................................................................................... 91
● Configuring ACP Measurements.............................................................................92
4.3.8.1 Main Settings
Contains general characteristics of the signal analyzer.
Measurement Data Source........................................................................................... 89
System Bandwidth........................................................................................................ 89
Periods to Capture........................................................................................................ 90
Trigger Mode.................................................................................................................90
Measurement Bandwidth.............................................................................................. 90
Use Wideband Measurement Path............................................................................... 91
Measurement Data Source
Selects the source of the I/Q data.
You can get the measurement data at the DUT output in three ways:
●
"Hardware"
Data recording by measuring the data with an analyzer
●
"File"
Import the data you want to measure via a file
●
"Internal simulation"
Simulate a DUT according to specification.
Remote command:
CONF:IQSINK:SOUR HW | FILE | SIM
System Bandwidth
Defines the bandwidth of the system under test.
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The system bandwidth is the baseband bandwidth available for signal generation and
DPD calculation.
For more information see
●
"Link Clock to System Bandwidth" on page 61
●
"Manual Generator Clock Rate / Resulting Generator Clock Rate" on page 63
Remote command:
CONF:IQSINK:BW <numeric value>
Periods to Capture
Defines the number of I/Q reference signal data blocks that the R&S FS-K130PC uses
for averaging purposes.
The R&S FS-K130PC can average I/Q data in both amplitude and phase. When averaging data, the R&S FS-K130PC increases the recording length in order to capture the
number of signal periods that you have defined here within one I/Q recording within the
capture buffer.
Remote command:
CONF:IQSINK:AVG <numeric value>
Trigger Mode
Selects the trigger that initiates the measurement.
Typically, the marker output of the generator is connected to the trigger input of the
analyzer to indicate the start of a signal. This trigger may not be available if, for example, you generate the reference signal with an external generator. In that case, you
have to increase the recording length to three reference signal periods in order to capture the requested amount of data under all circumstances.
●
"Immediate trigger"
The data capture starts as soon as the analyzer is ready.
●
"External trigger"
The data capture starts as soon as the analyzer recognizes a trigger event at its
input.
Note: The immediate trigger is not available in case of signals that are not periodic.
The immediate trigger also slightly slows down the measurement because snychronization takes more time.
Remote command:
CONF:IQSINK:TRIG:MODE IMM | EXT
Measurement Bandwidth
Defines the resolution bandwidth for I/Q and auto-level measurements.
If you set the resolution bandwidth automatically, R&S FS-K130PC sets the smallest
available bandwidth that is greater than 1.5 times the sampling rate.
Note: Some analyzers ignore the measurement bandwidth defined here. Instead they
determine the bandwidth directly from the sampling rate you have set. For more information refer to the documentation of the analyzer (➙ TRACe:IQ remote commands).
Remote command:
CONF:IQSINK:MBW <numeric value>
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Use Wideband Measurement Path
Turns the wideband path for a higher measurement bandwidth on and off.
Note that a higher measurement bandwidth might add unwanted effects (e.g.
increased noise) to the measurement.
Wideband measurement paths are available with hardware options for the R&S FSQ,
R&S FSV and R&S FSW. For more information refer to the datasheet of the analyzers.
Remote command:
CONF:IQSINK:WBAN ON | OFF
4.3.8.2 Response File Settings
Defines the characteristics of a file that contains the characteristics of the reference
signal.
File Type....................................................................................................................... 91
Stimulus and Response File Name...............................................................................91
Stimulus and Response File Name (Secondary File)................................................... 91
File Type
Opens the "Data File Format Definition" dialog box to import various standard signal
type or generic I and Q data files.
The "Data File Format Definition" dialog box contains functionality to define the file format in case you are using reference signal information from a file.
For more information see
●
chapter 4.5, "Specifying the File Type", on page 107
Remote command:
I/Q Generator: CONF:IQGEN:FILE:TYPE <TYPE>
I/Q Recorder: CONF:IQSINK:FILE:TYPE <TYPE>
<TYPE>: BIN1 | BIN2 | ASC1 | ASC2 | MAT | M | IQW | IBN | WV |
FSX | SIM | DSUIT
Stimulus and Response File Name
Selects the file that contains the reference or measurement signal information.
Remote command:
I/Q Generator: CONF:IQGEN:FILE:NAME 'string'
I/Q Recorder: CONF:IQSINK:FILE:NAME 'string'
Stimulus and Response File Name (Secondary File)
Select a secondary file that contains the reference or measurement signal information.
Selecting a secondary file is necessary only if you use a file type that requires two files.
Remote command:
I/Q Generator: CONF:IQGEN:FILE:NAME2 'string'
I/Q Recorder: CONF:IQSINK:FILE:NAME2 'string'
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4.3.8.3 Configuring ACP Measurements
Defines characteristics for ACP measurements.
Number of ACP Channels.............................................................................................92
Relative ACP Channel Spacing.................................................................................... 92
Channel Bandwidth....................................................................................................... 92
RBW (Resolution Bandwidth)........................................................................................92
Sweep Time Multiplier...................................................................................................93
Sweep Time Limit..........................................................................................................93
System Bandwidth Overrides Auto Span...................................................................... 93
Use Noise Correction.................................................................................................... 93
Number of ACP Channels
Defines the number of adjacent channels for ACP measurements.
Each channel you add, adds one channel to the left and one to the right of the Tx
channel.
Remote command:
CONF:IQSINK:ACP:CHAN <numeric value>
Relative ACP Channel Spacing
Defines a (relative) spacing between the channels.
A ratio of
●
1 results in channels being adjacent to each other with no space between but no
interference
●
< 1 results in channels interfering with each other
●
> 1 results in a space between the channels
Remote command:
CONF:IQSINK:ACP:SPAC <numeric value>
Channel Bandwidth
Defines the bandwidth of the adjacent channels (ACP channels).
By default, the software automatically detects and selects the channel bandwidth for
the adjacent channels. This is based on the bandwidth of the transmission channel.
Remote command:
CONF:IQSINK:ACP:BWID
RBW (Resolution Bandwidth)
Defines the resolution bandwidth used for ACP measurements.
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By default, the software automatically detects and defines the resolution bandwidth
based on the bandwidth of the adjacent channel.
Remote command:
CONF:IQSINK:ACP:RBW
Sweep Time Multiplier
Defines a factor to increase the ACP measurement sweep time by.
The basic sweep time ("Multiplier" = 1) is automatically calculated by the software.
Changing the multiplier increases the sweep time by the defined factor. Thus, the complete sweep time is calculated according to:
(ReferenceSignalPeriod * NumberOfTracePoints) * SweepTimeMultiplier
Increasing the sweep time stabilizes ACP measurement results and decreases noise.
Remote command:
CONF:IQSINK:ACP:SWE:MUL <numeric value>
Sweep Time Limit
Defines a maximum sweep time to limit the length of measurements.
The sweep time may become very long if the repitition period is long. Thus, limiting the
sweep time is a way to keep measurements in a reasonable time frame. If the automatically calculated sweep time exceeds the sweep time limit, the R&S FS-K130PC uses
the sweep time limit as the sweep time for subsequent measurements.
Remote command:
CONF:IQSINK:ACP:SWE:LIM <numeric value>
System Bandwidth Overrides Auto Span
Turns automatic calculation of the displayed frequency range on and off if the system
bandwidth is greater than the calculated span.
By default, the software automatically calculates the frequency range that is displayed,
regardless of the system bandwidth. In that case, it may be that parts of the signal are
not displayed.
To view the complete signal bandwidth, you can expand the displayed frequency range
to the value of the system bandwidth by turning the override on.
Remote command:
CONF:IQSINK:ACP:SBW ON | OFF
Use Noise Correction
Turns noise cancellation on and off.
If you are using noise correction, the results are corrected by the inherent noise of the
analyzer you are using. The inherent noise of the analyzer is determined with a reference measurement that is performed before the actual measurement.
Remote command:
CONF:IQSINK:NCOR
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Defining the DSP Properties
4.4 Defining the DSP Properties
In order to configure the signal processing, you can adjust various parameters in the
DSP properties dialog box.
►
Click on the
button or select the "DSP Configuration" menu item from the "Win-
dows" menu.
The "DSP Properties" dialog box opens.
● Signal Flow..............................................................................................................94
● DSP Options........................................................................................................... 96
● Signal Synchronization............................................................................................97
● Error Compensation................................................................................................98
● Generic Parameter Calculation...............................................................................98
● Channel Estimation.................................................................................................99
● System Modeling (General).................................................................................. 100
● System Modeling (Polynomial)..............................................................................102
● System Modeling (Spline)..................................................................................... 104
● System Modeling (Memory Polynomial)................................................................104
● System Modeling (Volterra)...................................................................................105
● Appendix: Remote Commands to Configure Polynomial Models......................... 105
4.4.1 Signal Flow
Controls the main calculation steps that are performed by the software.
Sync Mode.................................................................................................................... 94
Channel Estimation....................................................................................................... 95
Modeling........................................................................................................................95
Detect Pulses In Reference Signal............................................................................... 96
DPD Mode.....................................................................................................................96
Sync Mode
Selects the method of synchronization for the reference and measurement signal. An
exact synchronization is necessary to calculate a correct DUT model.
●
"Off"
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Performs no synchronization. Use this if you, e.g. create both signals with an EDA
tool like Matlab and provide them in a file.
●
"Timing, Phase and Gain"
Estimates a reduced set of parameters
●
"Frequency, Timing, Phase, Gain, IQ Parameter"
Estimates the full set of parameters
In general, it is recommended to select the last configuration, e.g. if the instruments
do not have reference frequencies coupled and a full set of parameters is to be
estimated.
If the reference frequencies are coupled, you can use "Timing, Phase and Gain". If
both signals are already aligned correctly, switch the sync mode off. This also
speeds up the signal processing.
Note that only "Frequency, Timing, Phase, Gain, IQ Parameter" supports I/Q averaging.
Remote command:
CONF:DSP:FLOW:SYNC OFF | TPG | ALL
Channel Estimation
Turns the calculation of amplitude and phase response for the synchronized data on
and off.
If you are not interested in the channel impulse response, switch channel estimation
off. This also speeds up the signal processing.
Remote command:
CONF:DSP:FLOW:CEST OFF | FFT | LIKELI
Modeling
Selects the method of DUT model calculation.
The following models are available:
●
"Off"
Performs no modeling; useful e.g. if you are interested in the raw EVM only.
●
"Polynomial"
Calculates a polynomial model - old version from R&S FS-K130PC Version 1.0
●
"Polynomial enhanced"
Calculates a polynomial model with higher performance, more configurability and
better stability in high-nonlinear regions.
●
"Spline"
Calculates a memory-free model using spline approximation techniques.
●
"Memory polynomial"
Calculates a polynomial model with memory effects but no intermix between different delay states.
●
"Volterra"
Calculates a polynomial model with memory effects and intermix between different
delay states.
Remote command:
CONF:DSP:FLOW:MOD OFF | POLY_OLD | POLY | SPLINE | MEMPOLY |
VOLTERRA
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Detect Pulses In Reference Signal
Turns pulse detection in the reference signal on and off.
If on, the software tries to detect the On and Off regions of the pulses and their characteristics in unknown signals. This can be useful if you playback previously recorded
signals or analyze signals from a file whose characteristics are unknown.
Remote command:
CONF:DSP:FLOW:PDET ON | OFF
DPD Mode
Selects the mode the DPD (digital predistortion) calculation is based on.
The R&S FS-K130PC uses the DPD to predistort the existing I/Q data that you have to
measure the DUT behavior. After applying the DPD to the reference signal and to the
DUT, the output signal of the DUT should have a better performance with regards to
ACP and/or EVM.
Remote command:
CONF:DSP:FLOW:DPD NONE | ONCE
4.4.2 DSP Options
Defines general DSP options.
Resampling Post-Filter..................................................................................................96
Resampling Cut-Off Dynamics......................................................................................96
Resampling Post-Filter
Turns an additional lowpass filter that, if necessary, is used to process the resampled
signal on and off.
The filter removes any unwanted frequency components outside the useful signal
bandwidth that may have been generated if the original signal and the resampled signal have a different clock rate.
If the filter is on, the software determines the useful signal bandwidth before resampling the signal. After resampling, the filter removes any frequency components outside
of the useful signal bandwidth.
For more information see "Resampling Cut-Off Dynamics" on page 96.
Remote command:
CONF:DSP:GEN:RSAM:STAT ON | OFF
Resampling Cut-Off Dynamics
Defines the minimum distance to the peak power that a signal must have in order to be
recognized for the calculation of the useful signal bandwidth.
During the calculation of the useful signal bandwidth, the R&S FS-K130PC looks for
the first signals to the left and to the right of the main signal that fall below this threshold. These bandwidth between these signals then define the useful signal bandwidth.
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The useful signal bandwidth in turn defines the range in which the resampling post-filter may be applied.
For more information see "Resampling Post-Filter" on page 96.
Remote command:
CONF:DSP:GEN:RSAM:CUT <numeric value>
4.4.3 Signal Synchronization
Optimizes the matching of the reference signal and the measured signal.
Periods to analyze.........................................................................................................97
Search Tolerance..........................................................................................................97
Rough Correlation Sync Domain...................................................................................97
Periods to analyze
Defines the maximum number of analyzed reference signal periods within the measurement signal.
When analyzing data from a file, the file content may change over time, e.g. when the
file starts with the reference signal but then continues with a different signal content. A
case like that would lead to correlation and synchronization errors.
To avoid such erros, you can use this parameter to limit the analysis to a particular
number of reference signal periods. For example, setting the periods to analyze to 1,
analyzes only one period of the reference signal within the measurement signal.
Remote command:
CONF:DSP:SYNC:AVG <numeric value>
Search Tolerance
Defines the percentage of reference signal periods to try to sync besides one reference
signal period within the measurement signal.
For the typical applications, you should not change the search tolerance.
Remote command:
CONF:DSP:SYNC:TOL <numeric value>
Rough Correlation Sync Domain
Selects the correction method used for the rough estimation during signal synchronization.
Signal synchronization is a 2-step algorithm. The first step is a rough estimation on
only a few parameters. The "Rough Correlation Sync Domain" applies to that step. You
can select either "Magnitude" or "IQ" domain.
The second step of the algorithm is a fine estimation that includes all parameters to
estimate.
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Note: In case of signals that contain AM components only, you have to run the rough
estimation on the "Magnitude" of the signal to get stable results. This is because in
case of AM signals, the quadrature part of the signal is close to 0.
Remote command:
CONF:DSP:SYNC:DOM IQ | MAG
4.4.4 Error Compensation
Contains ways to compensate for errors during signal processing.
Compensate <DSP Parameter>................................................................................... 98
Compensate <DSP Parameter>
Turns error compensation for one of the DSP parameters from the measurement signal
on and off.
You can compensate the following DSP parameters:
●
I/Q Imbalance
●
I/Q Offset
●
Frequency Error
●
Timing Offset
●
Amplitude Droop
All parameters are estimated during the signal synchronization. Turn off the compensation for each parameter individually, so this error in the measurement signal will no be
corrected.
Remote command:
I/Q imbalance: CONF:DSP:SYNC:COMP:IQIM ON | OFF
I/Q offset: CONF:DSP:SYNC:COMP:IQOF ON | OFF
Frequency error: CONF:DSP:SYNC:COMP:FREQ ON | OFF
Timing offset: CONF:DSP:SYNC:COMP:TIME ON | OFF
Amplitude droop: CONF:DSP:SYNC:COMP:DROOP ON | OFF
Gain: CONF:DSP:SYNC:COMP:GAIN ON | OFF
4.4.5 Generic Parameter Calculation
Contains generic DSP characteristics.
Nonlinear Estimation Order...........................................................................................99
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Nonlinear Estimation Order
Defines the supposed nonlinear order of the DUT used to estimate the nonlinear
parameters.
The IP3 or IP5, for example, are derived from parameters of a nonlinear equation. The
equation that is used to this end has a specific order that can not be estimated.
The nonlinear estimation order sets the order you need to calculate the equation.
If the order is set too high, too much energy may be spread to high-order terms, leading to wrong measurement results in lower orders and thus errors in the calculation of
genereic parameters like the IP3.
Remote command:
CONF:DSP:GEN:NLORD <numeric value>
4.4.6 Channel Estimation
Defines the channel estimation characteristics.
The channel estimation process calculates the amplitude and phase response of the
DUT. It also controls that spectral components that do not have enough power do not
contribute on the impulse response calculation.
Impulse Response Taps............................................................................................... 99
Impulse Response Overlap...........................................................................................99
Impulse Response Taps
Defines the number of taps R&S FS-K130PC uses to calculate the impulse response.
The number is the sampling point count for calculating the impulse response from the
reference and measurement data.
Remote command:
CONF:DSP:CEST:TAPS <numeric value>
Impulse Response Overlap
Defines the overlap ratio for the impulse response calculation.
The R&S FS-K130PC calculates the impulse response via time-domain to frequencydomain conversion using FFT. The FFT width is defined with the impulse response
taps. If the signal is longer than the number of taps (typical measurement case), the
signal processing steps over the signal in a step size defined by the impulse response
overlap.
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Example:
The number of impulse response taps is 1024, the impulse response overlap is 50 %
and the number of reference and measurement samples is 4096. The FFTs are calculated with a length of 1024, and the start points of the individual FFTs are 0, 512, 1024,
1536, 2048, 2560, 3072 and 3584, relative to the 1st measurement sample.
Remote command:
CONF:DSP:CEST:OVER <numeric value>
4.4.7 System Modeling (General)
Defines general charcateristics of the signal model.
Modeling Range.......................................................................................................... 100
Range Size..................................................................................................................100
Pulse Detection Limit.................................................................................................. 100
Maximum Model EVM and DPD Degradation.............................................................101
Upsampling Order....................................................................................................... 101
Quantization Points..................................................................................................... 101
Curve Inversion Segments..........................................................................................101
Estimate I/Q Imbalance...............................................................................................101
Dual-Tone Filtering......................................................................................................102
Modeling Range
Selects the range of the signal to perform the modeling and DPD calculation on.
Selecting a range is useful, for example if the complete signal is very long and needs a
long time to process. Usually, a small number of samples around the peak is enough
for correct model calculation.
Remote command:
CONF:DSP:MOD:RANG FULL | PEAK
Range Size
Defines the size of the modeling range if the model is applied to a particular range of
the model only.
Remote command:
CONF:DSP:MOD:SIZE <numeric value>
Pulse Detection Limit
Defines the level threshold for pulse detection.
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