Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this
publication supersedes that in all previously published material. Specifications and p rice change privileges
reserved.
TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.
Online help version: 2.7
Contactin
Tektronix, Inc.
14150 SW Karl Braun Drive
P. O . B o x 5 0 0
Beaverton, OR 97077
USA
For product information, sales, service, and technical support:
g Tektronix
In North America, call 1-800-833-9200.
Worldwide, visit www.tektronix.com to find contacts in your area.
RSA6100B Series & RSA5100A Series Printable Helpix
Table of Contents
xRSA6100B Series & RSA5100A Series Printable Help
Welc omeWelc ome
Welcome
This help provides in-depth information on how to use the RSA6100B Series Real-Time Spectrum
Analyzers and RSA5100A Series Real-Time Signal Analyzers. This help contains the most complete
description
the RSA6100B Series Real Time Signal Analyzer and RSA5100A Series Real-Time Signal AnalyzerQuick Start User Manual. To see tutorial examples of how to use your analyzer to take measurements
in different application areas, refer to the RSA6100B Series Real Time Signal Analyzer and RSA5100ASeries Real-Time Signal Analyzer Application Examples Reference.
This help provides in-depth information on how to use the SignalVu™ Vector Signal Analysis Software.
This help is also available in a PDF format for printing.
NOTE. Most of the screen illustrations in this document are taken from the vector signal analysis software
version
hardware-based functionality and buttons, such as Trig, that are not present in the SignalVu™ application.
s of how to use the analyzer. For a shorter introduction to the Signal Analyzer, refer to
that runs on the RSA5100A Real-time Signal Analyzers. These instruments support additional
RSA6100B Series & RSA5100A Series Printable Help1
Welc omeWelcome
2RSA6100B Series & RSA5100A Series Printable Help
About Tektronix AnalyzersYour Tektronix Analyzer
Your Tektronix Analyzer
The RSA6100B Series and RSA5100A Series Analyzers will help you to easily discover design issues that
other signal analyzers may miss. The revolutionary DPX display offers an intuitive live color view of signal
transients c
your design, or instantly displaying a fault when it occurs. This live display of transients is impossible
with other signal analyzers. Once a problem is discovered with DPX, the Tektronix Analyzers can be set to
trigger on the event, capture a continuous time record of changing RF events and perform time-correlated
analysis in all domains. You get the functionality of a wideband vector signal analyzer, a spectrum analyzer
and the unique trigger-capture-analyze capability of a Real-Time Analyzer – all in a single package.
Discover
hanging over time in the frequency domain, giving you immediate confidence in the stability of
RSA6100B Series: Tektronix exclusive 40 MHz and 110 MHz DPX Density and Frequency Mask
triggers (Option 02) offer easy event-based capture of transient RF signals by triggering on any
change in the frequency domain.
RSA5000A Series: Tektronix exclusive 25 MHz, 40 MHz, and 85 MHz DPX Density and Frequency
Mask triggers (Option 52) offer easy event-based c apture of transient RF signals by triggering on
any change in the frequency domain.
ture
Cap
RSA6100B Series: All signals within a 110 MHz bandwidth span are captured into memory (Option
0 only, 40 MHz acquisition bandwidth standard).
11
RSA5000A Series: All signals within a 85 MHz bandwidth span are captured into memory (Option 85
nly, 40 MHz acquisition bandwidth with Option 40, and 25 MHz standard).
o
RSA6100B Series: Up to 7 seconds acquisition length at 110 MHz bandwidth provides complete
analysis over time without making multiple acquisitions.
RSA5100A Series: Up to 7 seconds acquisition length at 85 MHz bandwidth provides complete
analysis over time without making multiple acquisitions.
RSA6100B Series & RSA5100A Series Printable Help3
About Tektronix AnalyzersProduct Description
Analyze
Extensive time-correlated multi-domain displays connect problems in time, frequency, phase and
amplitude for quicker understanding of cause and effect when troubleshooting.
Power measurements and signal statistics help you characterize components and systems: ACLR,
Multi-Carrier ACLR, Power vs. Time, CCDF, Phase Noise, and Spurious.
Advanced Measurement Suite (Opt. 20): Pulse measurements including rise time, pulse width, duty,
ripple, power, frequency and phase provide deep insight into pulse train behavior.
General Purpose Digital Modulation Analysis (Opt. 21): Provides vector signal analyzer functionality.
Product Description
SignalVu™ vector signal analysis software helps you easily validate wideband designs and ch
wideband spectral events. By combining the signal analysis engine of the RSA6100B Real-Time Analyzer
with that of the industry’s widest bandwidth digital oscilloscopes, designers can now evaluate complex
signals up to 20 GHz without the need of an external down converter. You get the functionality of a vector
signal analyzer, a signal analyzer and the powerful trigger capabilities of a digital oscilloscope, all in a
single package. Whether your design validation needs include wideband radar, high data rate satellite
links or frequency hopping communications, SignalVu vector signal analysis software c
time-to-insight by showing you time variant behavior of these wideband signals.
aracterize
an speed your
Key Features
Tightly integrated software and hardware control allows you to easily switch between SignalVu and
oscilloscope user interfaces to optimize triggers and other acquisition parameters. Key features of
SignalVu include:
Direct observation of microwave signals to 20 GHz without an external down converter
All signals up to the analog bandwidth of oscilloscope are captured in memory
Customizable oscilloscope acquisition parameters for effective use of capture memory
Four channel acquisitions help you correlate independent RF events
Apply custom math and filtering to acquisition channels
Extensive time-correlated, multi-domain displays connect problems in time, frequency, phase and
amplitude for quicker understanding of cause and effect when troubleshooting
Power measurements and signal statistics help you characterize components and systems: ACLR,
Multi-Carrier ACLR, Power vs. Time, CCDF, OBW/EBW, and Spur Search
Advanced Signal Analysis Suite (Opt. SVP) provides automated pulse measurements including rise
time, pulse width and pulse-to-pulse phase provide deep insight into pulse train behavior
General Purpose Digital Modulation Analysis (Opt. SVM) provides vector signal analyzer
functionality
4RSA6100B Series & RSA5100A Series Printable Help
About Tektronix AnalyzersProduct Software
Settling Time Measurements (Option SVT) provides Frequency and Phase settling time measurements
Flexible OFDM Analysis (Option SVO) provides measurements for OFDM signals specified by
Tektronix OpenChoice® enables easy transfer to a variety of analysis programs such as Excel and
Matlab
Product Software
The instrument includes the following software:
RSA6100B Series System Software: The RSA6100B Series product software runs on a specially
configured version of Windows 7. As with standard Windows 7 installations, you can install other
compatible applications, but the installation and use of non-Tektronix software is not supported by
Tektronix. If you need to reinstall the operating system, follow the procedure in the Restoring theOperating System chapter in the RSA6100B Series Real-Time Signal Analyzers Service manual
(Tektronix part number 077-0648-XX). You can download a PDF version o f the Service manual
at www.tektronix.com/manuals
provided by Tektronix for use with your instrument.
. Do not substitute any version of Windows that is not specifically
RSA5100A System Software: The RSA5100A Series product software runs on Windows 7. As with
standard Windows 7 installations, you can install other compatible applications, but the installation
and use of non-Tektronix software is not supported by Tektronix. If you need to reinstall the operating
system, follow the procedure in the Restoring the Operating System chapter in the RSA5100A
Series Real-Time Signal Analyzers Service manual (Tektronix part number 077-0522-XX). You can
download a PDF version of the Service manual at www.tektronix.com/manuals
version of Windows that is not specifically provided by Tektronix for use with your instrument.
Product Software: The product software is the instrument application.
(UI) and all other instrument control functions. You can minimize o r even exit/restart the instrument
application as your needs dictate.
Occasionally new versions of software for your instrument may become available at our Web site. Visit
www.tektronix.com/software
Software and Hardware Upgrades
Tektronix may offer software or hardware upgrade kits for this instrument. Contact your local Tektronix
distributor or sales office for more information.
Standard Accessories
. Do not substitute any
It provides the user interface
for information.
The standard accessories for the RSA6100B Series and RSA5100A Series instruments are shown below.
For the latest information on available accessories, see the Tektronix Web site
RSA6100B Series & RSA5100A Series Printable Help5
.
About Tektronix AnalyzersStandard Accessorie s
Quick Start User Manual
English - Option L0, Tektronix part number 071-2838-XX
Japanese - Option L5, Tektronix part number 071-2840-XX
Russian, Option L10, Tektronix part number 071-2841-XX
Simplified C
hinese - Option L7, Tektronix part number 071-2839-XX
Applications Instructions
English – Tektronix part number 071-2834-XX
Simplifie
Japanese - Option L5, Tektronix part number 071-2836-XX
Russian, Option L10, Tektronix part number 071-2837-XX
Product
The Product Documentation CD-ROM contains PDF versions of all printed manuals. The Product
Docume
PDF format:
RSA61
Instructions manual PDF, Tektronix part number 077-0521-XX
RSA6
RSA5100A Series Service Manual PDF, Tektronix part number 077-0522-XX
d Chinese - Option L7, Tektronix part number 071-2835-XX
Documentation CD-ROM
ntation CD-ROM also contains the following manuals, some of which are available only in
00B Series and RSA5100A Series Real-Time Signal Analyzers Declassification and Security
100B Series Service Manual PDF, Tektronix part number 077-0648-XX
RSA6100B Series and RSA5100A Series Programmer Manual PDF, Tektronix part number
077-0523-XX
RSA6100B Series Specifications and Performance Verification PDF, Tektronix part number
077-0647-XX
RSA5100A Series Specifications and Performance Verification PDF, Tektronix part number
077-0520-XX
Other related materials
NOTE. To check for updates to the instrument documentation, browse to www.tektronix.com/manuals
and search by your instrument's model number.
6RSA6100B Series & RSA5100A Series Printable Help
About Tektronix AnalyzersRecommended Accessories
Important Documents Folder
Certificate of Calibration documenting NIST traceability, 2540-1 compliance, and ISO9001 registration
Power Cords
North America - Option A0, Tektronix part number 161-0104-00)
Universal Euro - Option A1, Tektronix part number 161-0104-06
United Kingdom - Option A2, Tektronix part number 161-0104-07
Australia - Option A3, Tektronix part number 161-0104-05
240V Nort
Switzerland - Option A5, Tektronix part number 161-0167-00
Japan - Option A6, Tektronix part number 161-A005-00
China - Option A10, Tektronix part number 161-0306-00
India - Option A11, Tektronix part number 161-0324-00
No power cord or AC adapter - Option A99
h America - Option A4, Tektronix part number 161-0104-08
Optical Wheel Mouse
Product Software CD
RF Input Connectors (RSA6100B Series)
nar Crown® RF input connector - Type N (RSA6106B, RSA6114B), Tektronix part number
Pla
131-4329-00
anar Crown® RF input connector - 3.5 mm female (RSA6120B), Tektronix part number 131-9062-00
Pl
Recommended Accessories
The recommended accessories for the RSA6100B Series and RSA5100A Series instruments are shown in
the following table. For the latest information on available accessories, see the Tektronix Web site
RSA6100B Series & RSA5100A Series Printable Help7
.
About Tektronix AnalyzersOptions
Item
Additional Re
Series Option 56 (Windows 7 and instrument software
installed)
Additional Removable Hard Drive for use with RSA5100A
Series Optio
installed)
Transit Case
Rackmount I
Additional Quick Start User Manual (paper)
Additional Documents CD (all manuals in PDF format)
xxx
Options
To view a listing of the software options installed on your instrument, select Help > About Your
Tektronix Real-Time Analyzer. There is a label on the rear-panel of the instrument that lists installed
hardware options.
To view a listing of the software options installed in your software, select Help > About Your TektronixVector Signal Analysis Software.
Options can be added to your instrument. For the latest information on available option upgrades, see
the Tektronix Web site
movable Hard Drive for use with RSA6100B
n 56 (Windows 7 and instrument software
nstallation Kit
.
Ordering part n
065-0751-XX
065-0852-00
016-2026-X
RSA56KR
071-2838-
063-4314-
X
XX
XX
umber
Documentation
In addition to the help, the following documents are available:
ck Start User Manual (071-2838-XX - English). The Quick Start User Manual has information
Qui
about installing and operating your instrument. The Quick Start User Manual is also available in
Simplified Chinese (071-2839-XX), Japanese (071-2840-XX), and Russian (071-2841-XX).
Application Examples Reference (071-2834-XX). The Application Examples Reference provides
examples of specific application problems and how to solve those problems using an RSA6100B
Series Signal Analyzer. The Application Examples Reference is also available in Simplified Chinese
(071-2835-XX), Japanese (071-2836-XX), and Russian (071-2837-XX).
Programmer Manual (077-0523-XX). The Programmer Manual is provided as a printable PDF file,
which is located on the Documents CD. See the Documents CD-ROM for installation information.
Service Manual (RSA6100B Series: 077-0648-XX, RSA5100A Series: 077-0522-XX). The Service
manual is provided as a printable PDF file, which is located on the Documents CD. See the Documents
CD-ROM for installation information. The Service manual includes procedures to service the
instrument to the module level and restore the operating system.
8RSA6100B Series & RSA5100A Series Printable Help
About Tektronix AnalyzersDocumentation
Specifications and Performance Verification Technical Reference Manual (RSA6100B Series:
077-0647-XX, RSA5100A Series: 077-0520-XX). This is a PDF-only manual that includes both the
specification
Declassification and Security Instructions (RSA6100B Series a nd RSA5100A Series:
077-0521-XX
memory devices from the instrument. It is located on the Documents CD.
s and the performance verification procedure. It is located on the Documents CD.
) This document helps customers with data security concerns to sanitize or remove
SignalVu Re
of the SignalVu software. It identifies elements of the SignalVu screen, elements of different displays
andincludesamenutree. TheReferenceManualisprovidedasaprintablePDFfile.
SignalVu Programmer Manual (077-0223-XX). This document provides supplementary information
about the remote commands for the SignalVu software. The Programmer Manual is provided as a
printable PDF file. For detailed descriptions of the remote commands, see the RSA6100B Series
Real-Time Spectrum Analyzers, RSA5100A Series Real-Time Signal Analyzers Programmer Manual
(077-0523-XX) and the DPO7000, DPO70000B/C, DSA70000B/C, MSO70000/C, MSO5000, and
DPO5000
SignalVu Printable Help Document (PDF) (077-0225-XX). A PDF file version of the help that
can eas
The SignalVu documentation PDFs are located on the Optional Applications Software for Windows-Based
loscopes DVD.
Oscil
The most recent versions of the product documentation, in PDF format, can be downloaded from
tektronix.com/manuals
www.
ference (Tektronix part number 077-0224-XX). This document provides a brief overview
Series Digital Oscilloscopes Programmer Manual (077-0010-10 or later).
ily be printed.
. You can find the manuals by searching on the product name.
Other Documentation
Your instrument includes supplemental information on CD-ROM:
cuments CD (Tektronix part number 063-4314-XX)
Do
RSA6100B Series & RSA5100A Series Printable Help9
About Tektronix AnalyzersDocumentation
10RSA6100B Series & RSA5100A Series Printable Help
External Trigger input connector, –2.5 V to +2.5 V (user settable).
RF input connector 50 Ω.
Connecting Signals and Selecting the Analysis Channel
SignalVu analyzes signals acquired by the oscilloscope. The SignalVu software analyzes one, two, or
four signals at a time, so you need to specify which oscilloscope input channels to use. Math and Ref
channels can also be selected.
To specify which oscilloscope channel is analyzed:
1. Select Settings > Acquire to display the Acquire control panel.
2. Select the desired signal type from the Signal Input drop-down list along the left side of the control
panel. Available choices are RF (uses one oscilloscope channel), IQ (uses two channels), and Diff IQ
(uses four channels).
3. On the Ve rtic al tab, use the Source drop-down list(s) to select the channels to analyze.
4. Use the oscilloscope controls in the TekScope application to achieve a stable, triggered signal.
For information on the oscilloscope input signal capabilities and how to trigger on a signal, see the
oscilloscope's help. Note that SignalVu does not control triggering on the oscilloscope; you will need to
use the oscilloscope triggering functions to achieve a stable, triggered signal on the oscilloscope.
RSA6100B Series & RSA5100A Series Printable Help11
OrientationFront-Panel Controls
Front-Panel Controls
Reference
1MediaDVD-RW or removable hard disk
2Displays
3
4Trigger
5
6Analysis
7
8
9Amplitude
10
xxx
ItemFunctionMenu Equivalent
drive.
Opens the Displays dialog box
enabling you to select which
displays to open.
SettingsOpens/closes the Settings control
panel for the selected display.
Opens/closes the Trigger control
panel. On the RSA5100A Series,
this button lights when the trigger
mode is set to Triggered.
Acquire
FreqPress to adjust the measurement
Span (Spectrum)
BW (Spectrum)
Opens/closes the Acquire control
panel.
Opens/closes the Analysis control
panel.
frequency.
Press to adjust the span or press
and hold to display the Freq & Span
control panel for the General Signal
Viewing displays.
Opens/closes the Amplitude control
panel.
Press to adjust the bandwidth or
press and hold to display the BW
control panel for the General Signal
Viewing displays.
Setup > Displays
Setup > Settings
Setup > Trigger
Setup > Acquire
Setup > Analysis
Setup > Analysis > Frequency
Setup > Amplitude
12RSA6100B Series & RSA5100A Series Printable Help
OrientationFront-Panel Controls
Reference
11
12
ItemFunctionMenu Equivalent
Run/StopStarts and stops acquisitions.Run > Start Run > Stop
Peak (Markers
section)
Moves the active marker to the
maximum peak of the trace in the
selected display. If markers are
turned off, the marker reference (MR)
will appear at the maximum peak.
13
Select (Markers
section)
Selects the next marker. If markers
are turned off, the MR m arker (marker
reference) will appear.
14
Define (Markers
section)
Opens the Markers control panel.
If markers are turned off, the MR
marker (reference) will appear.
15
Control knobChanges values in numeric and list
controls. Pressing the knob (clicking
it) is the same as pressing the Enter
key on a k eyboard.
16Arrow keysMove the Markers. The Up arrow
moves the selected marker to the
next highest peak. The down arrow
moves the selected marker to the
next lower peak value. The right and
left arrows move the selected marker
to the next peak.
17
18
Increment/decrement keys
Delete, (Markers
Increments or decrements the
selected value
Deletes the selected marker
section)
19
Add, (Markers
Add a marker to the selected trace
section)
20ReplayReplays the current acquisition record
21
SingleSets the Run mode to Single
Sequence
xxx
Markers > Peak
RSA6100B Series & RSA5100A Series Printable Help13
OrientationFront-Panel Controls
Reference
22KeypadEnters valu
23Enter
ItemFunctionMenu Equiva
es in numeric controls.
Completes
data entry in controls.
Same as pressing the Enter key on
an external keyboard.
xxx
Reference
24Recall
25
26
ItemFunctionMenu Equivalent
Opens the Recall dialog box.
SaveOpens the Save As dialog box.File > Save As
Touch Screen OffTurns the touch screen on and off. It
is off when lighted.
27HelpDisplays the help.
28Applic
Sets the instrum ent to the selected
Application Preset values.
29DPX
Sets the instrum ent to the selected
DPX Preset values.
30User
Sets the instrum ent to the selected
User Preset values.
31Preset
Returns the instrument to the default
or preset values.
xxx
lent
File > Recall
Help > Online Manual
Setup > More Presets > Application
Setup > More Presets > DPX
Setup > More Presets > User
Setup > Preset
14RSA6100B Series & RSA5100A Series Printable Help
OrientationFront-Panel Controls
Front-Panel Controls
The front-panel controls remain dedicated to oscilloscope control functions when SignalVu is running. The
front-panel buttons and knobs of the oscilloscope do not have any effect on the S ignalVu software settings.
NOTE. One but
will halt data acquisition in the SignalVu software.
Touch Scre
You c a n use
keyboard. Generally, touch can be used anywhere that click is mentioned in this help.
To disable the touch screen, push the front-p anel TouchScreenOffbutton. When the touch screen is off,
the button is lighted. You can still access the on-screen controls with a mouse or keyboard.
You can adjust the touch screen oper ation to your personal preferences. To adjust the touch screen settings,
from Windows, select Start > Control Panel > Touch Screen Calibrator.
NOTE. If the instrument is powered on in Windows Safe Mode, the touch screen is inoperative. You will
need to use a mouse or keyboard to restore normal operation.
ton that affects the SignalVu software is the Run/Stop button. Pressing the Stop button
en
touch to control the instrument in addition to the front-panel controls, mouse, or extended
Touch-Screen Actions
You can use the touch screen to change marker settings and how waveforms are displayed by using the
Touch-screen Actions menu.
RSA6100B Series & RSA5100A Series Printable Help15
OrientationTouch-Screen Actions
To use the Touch-screen Actions menu, touch the display in a graph area and hold for one second, then
remove your finger. You can also use a mouse to display the Touch-screen Action menu by clicking
the right mouse button.
16RSA6100B Series & RSA5100A Series Printable Help
OrientationTouch-Screen Actions
IconMenuDescription
SelectSelects markers and adjusts their position.
Span Zoom
CF PanAdjusts the Center Frequency according to horizontal movement.
Zoom
Pan
-
-
-
-
-
-
xxx
ch-Screen Menu for Spurious Display
Tou
Reset Scale
Marker to peak
Next Peak
Add marker
Delete markerRemoves the last added marker.
All markers off
Trigger On ThisUse to visually define trigger parameters in the DPX display
Zooms the graph area about the selected point. Touch the graph
display at a point of interest and drag to increase or decrease the
span about the point of interest. Span Zoom adjusts the span
control and can affect the acquisition bandwidth.
Adjusts horizontal and vertical scale of the graph. The first
direction with enough movement becomes the primary scale of
adjustment. Adjustment in the secondary direction does not occur
until a threshold of 30 pixels of movement is crossed.
Dragging to the left or down zooms out and displays a smaller
waveform (increases the scale value). Dragging to the right or up
zooms in and displays a larger waveform (decreases the scale
value).
Adjusts horizontal and vertical position of the waveform. The first
direction with enough movement becomes the primary direction of
movement. Movement in the secondary direction does not occur
until a threshold of 30 pixels of movement is crossed.
Returns the horizontal and vertical scale and position settings
to their default values.
Moves the selected marker to the highest peak. If no marker is
turned on, this control automatically adds a marker.
Moves the selected marker to the next peak. Choices are Next
left, Next right, Next lower (absolute), and Next higher (absolute).
Defines a new marker located at the horizontal center of the graph.
Removes all markers.
(present only in the DPX S pectrum display).
The Touch-screen actions menu in the Spurious display has some minor changes compared to the standard
rsion used in other displays.
ve
RSA6100B Series & RSA5100A Series Printable Help17
OrientationTouch-Screen Actions
IconMenuDescription
-
-
-
xxx
lVu Markers Menu
Signa
Single-rangeChanges the current multi-range display to a single range display.
The displayed range is the range in which you display the
touchscreen-actions menu. Selecting Single-range from the menu
is equivalent to selecting Single on the Settings > Parameters tab.
Multi-range
Marker -> Sel Spur
Changes the current single-range display to a multi-range display.
Selecting Multi-range from the menu is equivalent to selecting
Multi on the Settings > Parameters tab.
Moves the selected marker to the selected spur.
The SignalVu Markers menu appears when you right-click (or touch and hold) on a marker. The SignalVu
ers menu enables you to assign a marker to a different trace, synchronize markers with oscilloscope,
Mark
cursors and pan the trace to place the marker at the measurement frequency.
18RSA6100B Series & RSA5100A Series Printable Help
OrientationElements of the Display
IconMenuDescription
-
-
-
-
xxx
Pan to marker
Assign to traceAssigns the selected marker to Trace 1, Trace 2, Trace 3 or the
Sync scope C1Synchronize
Sync scope C2Synchronizes the position of Cursor 2 with the location of the
Adjusts horizontal position of the waveform to locate the selected
marker at the m
Math trace. A t
selected marker. Turns on cursors if necessary.
selected marker. Turns on cursors if necessary.
easurement frequency.
race must be enabled to assign a marker to it.
s the position of Cursor 1 with the location of the
Elements o
The main a
ftheDisplay
reas of the application window are shown in the following figure.
Specific elements of the display are shown in the following figure.
RSA6100B Series & RSA5100A Series Printable Help19
OrientationElements of the Display
20RSA6100B Series & RSA5100A Series Printable Help
OrientationElements of the Display
Ref
Setting
number
1Displays
2Markers
3
SettingsOpens the Settings control panel for the selected display. E ach display has
4Trigger
5
Acquire
6Analysis
7
8
Frequenc
Reference LevelDisplays the reference level. To change the value, click the text and enter a
y
9Amplitude
10Repla
y
11Run
12
13Re
14
5
1
xxx
ck mark indicator
Che
call
SaveOpens the Save As dialog in order to save setup files, pictures (screen
reset
P
Description
Opens the Select Displays dialog box so that you can select measurement
displays.
Opens or closes the Marker toolbar at the bottom of the window.
its own cont
Opens the Tr
Opens the A
Opens the
rol panel.
igger control panel so that you can define the trigger settings.
cquire control panel so that you can define the acquisition settings.
Analysis control panel so that you can define the analysis settings
such as frequency, analysis time, and units.
Displays the frequency at which measurements are made. For spectrum
displays, this is called “Center Frequency”. To change the value, click the
text and
use the front panel knob to dial in a frequency. You can also enter
a frequency with the front panel keypad or use the front panel up and down
buttons.
number
Opens
from the keypad or use the front panel up and down buttons.
the Amplitude control panel so that you can define the Reference Level,
configure internal attenuation, and enable/disable the (optional) Preamplifier.
new measurement cycle on the last acquisition data record u sing any
Runs a
new settings.
Starts and stops data acquisitions. When the instrument is acquiring data, the
button label has green lettering. When stopped, the label has black lettering.
an specify the run conditions in the Run menu. For example, if y ou
You c
select Single Sequence in the Run menu, when you click the Run button,
the instrument will run a single measurement cycle and stop. If you select
tinuous, the instrument will run continuously until you stop the acquisitions.
Con
check mark indicator in the upper, left-hand corner of the display indicates
The
the display for which the acquisition hardware is optimized.
Displays the Open window in order to recall setup files, acquisition data files,
or trace files.
aptures), acquisition data files, or export measurement settings or acquisition
c
data.
Recalls the Preset (Main)
(see page 439) preset.
RSA6100B Series & RSA5100A Series Printable Help21
OrientationElements of the Display
Ref
Setting
number
1Recall
2
SaveOpens the Save As dialog in order to save setup files, pictures (screen
3Displays
4Markers
5
SettingsOpens the Settings control panel for the selected display. Each display has
6Acquire
7
8Amplitu
9
10
11Pres
12Repl
Analysis
de
Center FrequencyDisplays the Center Frequency. To change the value, click the text and enter the
ence Level
Refer
et
ay
13Run
xxx
Description
Displays the Open window in order to recall setup files, acquisition data files,
or trace files.
captures), a
cquisition data files, or export measurement settings or acquisition
data.
Opens the Select Displays dialog box so that you can select measurement
displays.
Opens or closes the Marker toolbar at the bottom o f the window.
its own co
Opens the
Opens th
ntrol panel.
Acquire control panel so that you can define the acquisition settings.
e Analysis control panel so that you can define the analysis settings
such as frequency, analysis time, and units.
Opens the Amplitude control panel so that you can define the Reference Level,
configure internal attenuation, and enable/disable the (optional) Preamplifier.
ency with a keyboard. For fine adjustments, you can use the mouse wheel.
frequ
ays the reference level. To change the value, click the text and enter a
Displ
number using a keyboard, or use a mouse scroll wheel.
Recalls the Preset (Main)
a new measurement cycle on the existing acquisition data record using
Runs
(see page 439) preset.
any new settings.
Starts and stops data acquisitions. When the instrument is acquiring data, the
button label has green lettering. When stopped, the label has black lettering.
can specify the run conditions in the Run menu. For example, if you
You
select Single Sequence in the Run menu, when you click the Run button,
the instrument will run a single m easur ement cycle and stop. If you select
ntinuous, the instrument will run continuously until you stop the acquisitions.
Co
22RSA6100B Series & RSA5100A Series Printable Help
OrientationRear-Panel Connectors
Rear-Panel Connectors
Left: RSA6100B Series; Right: RSA5100A Series
ItemDescripti
1
2
3
4,5
6
7
8Trig2 ln
9
10
11
12
13
14
5
1
xxx
AC Input,
GPIB
IF Outpu
Real Ti
+28 V DC
Microphone in; Headphone, audio output; and Line In connectors
COM 2, serial port for connecting peripherals
VGA external monitor output
PS2 keyboard input
USB2.0 ports for mouse and other peripherals (printers, external hard disks)
Ref Out, reference frequency output
Ref In, reference frequency input
E
on
main power connector
t (optional, RS A6100B only)
me IQ Output (optional)
Output, switched
thernet network connector
Setting Up Network Connections
Because the instrument is based on Windows, you configure network connections for the instrument the
samewayyouwouldforanyPCbasedonWindows.SeeHelp and Support in the Windows Start menu
to access the Windows Help System for information on setting up network connections.
RSA6100B Series & RSA5100A Series Printable Help23
OrientationSetting Up Network Connections
24RSA6100B Series & RSA5100A Series Printable Help
Operating Your InstrumentRestoring Default Settings
Restoring Default Settings
To restore the instrument to its factory d efault settings:
Select File > Preset (Main) to return the analyzer to its default settings.
Preset resets all settings and clears all acquisition data. Settings and acquisition data that have not been
saved will be lost.
Running Alignments
Alignments are adjustment procedures. Alignments are run by the instrument using internal reference
signals and measurements and do not require any external equipment or connections.
There are two settings for Alignments:
Automatically align as needed
Run alignments only when the Align Now button is pressed
If Automatically align as needed is selected, alignments run whenever the signal analyzer detects a
sufficient change in ambient conditions to warrant an alignment.
If Run alignments only when "Align Now" button is pressed is selected, the signal analyzer never runs
an alignment unless you manually initiate an alignment using the Align Now button.
NOTE. There are a few critical adjustments that must run occasionally even if Automatically align is
not enabled.
Alignment Status
When the signal analyzer needs to run an alignment, it displays a message on screen. If no message is
displayed, you can assume that the signal analyzer is properly aligned.
NOTE. If you must use the instrument before it has completed its 20-minute warm-up period, you should
perform an alignment to ensure accurate measurements.
Initiating an Alignment
1. Select Setup > Alignments.
2. Select the Align Now button.
The signal analyzer will run an alignment procedure. Status messages are displayed while the alignment
procedure is running. If the instrument fails the alignment procedure, an error message will be displayed.
RSA6100B Series & RSA5100A Series Printable Help25
Operating Your InstrumentPresets
If the instrument fails an alignment, run Diagnostics (Tools > Diagnostics) to see if you can determine
why the alignment failed.
NOTE. While an
Alignments during warm-up. During the 20-minute warm-up period, the signal analyzer will use the
alignment d
(if Auto mode is selected). During the specified period for warm-up, the instrument performance is not
warranted.
Alignments during normal operation. Once the signal analyzer reaches operating temperature±3 degrees C
(as detected inside the instrument), an alignment will be run. If an alignment becomes necessary during a
measurem
run. Once an alignment procedure is completed, the measurement cycle restarts.
NOTE. The first time the instrument runs after a software upgrade (or reinstall), the instrument will
perform a full alignment after the 20–minute warm-up period. This alignment cannot be aborted and it
occurs even if alignments are set to run only when manually initiated.
Align
Alignments are adjustment procedures run by the instrument using internal reference signals and
meas
traceable test equipment (signal sources and measuringequipment)toverifytheperformanceofthe
instrument.
ent cycle (if Auto mode is selected), the measurement is aborted and an alignment procedure is
ments Are Not Calibrations
urements. Calibrations can only be performed at a Tektronix service center and require the use of
alignment is running, both the IF and IQ outputs are disabled.
ata generated during the previous use of the instrument as it warms to operating temperature
Presets
Menu Bar: File > More presets > Preset options
e analyzer includes a set of configurations or presets that are tailored to specific applications. These
Th
configurations, referred to as Presets, open selected displays and load settings that are optimized to address
specific application requirements. There are three types of factory Presets: Main, Application, and DPX.
In addition to these factory defined Presets, you can create your own Presets, called User Presets, you
can recall to configure your analyzer.
SignalVu includes a set of configuration files that are tailored to specific applications. These configuration
files, referred to as Application Presets, open selected displays and load settings that are optimized to
address specific application requirements. You can add to the default application presets by creating your
own application presets. See Creating Application Presets
presets through the Application Presets menu item.
26RSA6100B Series & RSA5100A Series Printable Help
(see page 31). You access the application
Operating Your InstrumentPresets
Application PresetDescription
Modulation AnalysisThe Modulation Analysis setup application preset provides you with the most common
displays used during modulation analysis. Only present when Option 21 is installed.
Modulation AnalysisThe Modulation Analysis setup appl ication preset provides you with the most common
displays used during modulation analysis. Only present when Option SVM is installed.
Phase NoiseThe Phase N oise application preset opens the Phase Noise display, and makes changes
to the default parameters to settings better optimized for phase noise analysis. Only
present when
Option 11 is installed.
Pulse AnalysisThe Pulse Analysis application preset provides you with the most common displays used
during puls
e analysis, and makes changes to the default parameters to settings better
optimized for pulsed signal analysis. Only present when Option 20 is installed.
Pulse Analy
sis
The Pulse An
alysis application preset provides you with the most common displays used
during pulse analysis, and makes changes to the default parameters to settings better
optimized for pulsed signal analysis. Only present when Option SVP is installed.
Spectrum AnalysisThe Spectrum Analysis application preset provide you with the settings commonly used
l purpose spectrum analysis.
earch application preset c onfigures the instrument to show the Spurious
Spur Sear
9k-1GHz
equency Analysis
Time-Fr
ch Multi Zone
for genera
The Spur S
display with the frequency range set to 9 kHz to 1 GHz.
The Time-Frequency preset configures the instrument with settings suited to analyzing
signal behavior over time.
DPX PresetDescription
Open the DPX displayThe Open the DPX display opens the DPX display without closing existing displays.
me
Real Ti
The DPX Real Time P reset displays the DPX Spectrum display with the center frequency
set to 1.5 GHz and the span set to the maximum available real-time bandwidth.
SweptThe DPX Swept Preset displays the DPX Spectrum display with the center frequency
o1.5GHzandthespansetto3GHz.
set t
Span (RSA6100B Series
Zero
and RSA5100A with Option
PX Zero Span Preset displays the DPX Zero Span display with the center
The D
frequency set to 1.5 GHz and the sweep set to 1 ms.
200)
Main PresetsDescription
CurrentThis Preset sets the instrument to display a Spectrum display w ith settings matched
to show a Spectrum display with settings appropriate for typical spectrum analysis
sks. This preset was updated from the original factory preset with version 2.4 of the
ta
instrument software.
OriginalThis Preset is the original factory preset used with software versions 1.0 through 2.3.
This version of the factory preset is included to allow users to maintain compatibility with
xisting remote control software.
e
UserDescription
User Preset 1
This Preset is provided as a example for you to create your own Presets. This preset
displays the Spectrum, Spectrogram, Frequency vs Time, and Time Overview displays.
User Preset 2
This Preset is provided as a example for you to create your own Presets. This preset
displays the Spurious display configured to test for Spurious signals across four ranges.
xxx
Modulation Analysis
The Modulation Analysis application preset opens the following displays:
RSA6100B Series & RSA5100A Series Printable Help27
Operating Your InstrumentPresets
DPX display: Shows you a continuous spectrum monitoring of the specified carrier frequency.
Signal Quality: Shows a summary of modulation quality measurements (EVM, rho, Magnitude
Error, Phase Error, and others).
Constellation: Shows the I and Q information of the signal analyzed in an I vs. Q format.
Symbol Table: Shows the demodulated symbols of the signal.
To use the Modulation Analysis preset (assuming that Modulation Analysis is the selected preset on the list
of Application Presets and Preset action is set to Recall selected preset):
1. Select File > More presets > Application.
2. Set the mea
the DPX display.
3. Set the me
4. Set the reference level so that the peak of your signal is about 10 dB below the top of the DPX display.
5. Set the reference level so that the peak of your signal is about 10 dB below the top of the spectrum
display.
6. Set the modulation parameters for your signal. This includes the Modulation Type, Symbol Rate,
Measurement Filter, Reference Filter and Filter Parameter. All of these settings are accessed by
press
For most modulated signals, the Modulation Analysis application preset should present a stable display of
lation quality. Additional displays can be added by using the Displays button, and other settings can
modu
be modified to better align with your signal requirements.
surement frequency using the front-panel knob or keypad. Your signal should appear in
asurement frequency.
ing the Settings button.
Phase Noise
The Phase Noise application preset opens the Phase Noise display.
Pulse Analysis
The Pulse Analysis application preset opens the following displays:
DPX: The DPX display is opened with the maximum available span.
Time Overview: Shows amplitude vs. time over the analysis period.
Pulse Trace: Shows the trace of the selected pulse and a readout of the selected measurement from
the pulse table.
Pulse Measurement Table: This shows a full report for the user-selected pulse measurements.
You can make a selected pulse and measurement appear in the Pulse Trace display by highlighting it in the
Pulse Measurement Table. Key pulse-related parameters that are set by the Pulse Analysis application
preset are:
28RSA6100B Series & RSA5100A Series Printable Help
Operating Your InstrumentPresets
Measurement Filter: No Filter.
Measurement Bandwidth (RSA6100B Series): This is set to the maximum real-time b andwidth of
the instrument (40 MHz in a base instrument or 110 MHz with instruments with Option 110). Note:
The label on the “Measurement Bandwidth” setting is just “Bandwidth”. Like the main instrument
Preset comma
most other instrument controls to default values.
nd and the other application presets, the Pulse Analysis application preset also sets
Measuremen
the instrument (25 MHz in a base instrument or 40 MHz in instruments with Option 40, or 85 MHz
in instruments with Option 85). Note: The label on the “Measurement Bandwidth” setting is just
“Bandwidth”. Like the main instrument Preset command and the other application presets, the Pulse
Analysis application preset also sets most other instrument controls to default values.
Measurement Bandwidth: This is s et to the maximum real-time bandwidth of the instrument. Note:
The label on the “Measurement Bandwidth” setting is just “Bandwidth”. Like the main instrument
Preset command and the other application presets, the Pulse Analysis application preset also sets
most oth
Analysis Period: This is set to 2 ms to ensure a good probability of catching several pulses for
l signals.
typica
To use the Pulse Analysis preset (assuming that Pulse Analysis is the selected preset on the list of
cation Presets a nd Preset action is set to Recall selected preset):
Appli
1. Select File > More presets > Application.ClickOK.
2. Set the Center Frequency control to the carrier frequency of your pulsed signal.
3. Set the Reference Level to place the peak of the pulse signal approximately 0-10 dB down from
the top of the Time Overview display.
You may need to trigger on the signal to get a more stable display. This is set up in the Trigger control
panel. (“Trig” button). Using the Power trigger type with the RF Input source works well for many
pulsed signals.
t Bandwidth (RSA5100A Series): This is set to the maximum real-time bandwidth of
er instrument controls to default values.
You may need to trigger on the signal to get a more stable display. This is set up with the oscilloscope's
controls. A rising-edge trigger works well for many pulsed signals.
4. Set the Analysis Period to cover the number of pulses in your signal that you want to analyze. To do
this, click in the data entry field of the Time Overview window and set the analysis length as needed.
Spectrum Analysis
The Spectrum Analysis application preset opens a Spectrum display and sets several parameters. The
Spectrum Analysis preset sets the analyzer a s follows.
Spectrum Analysis : Sets the frequency range to maximum for the analyzer, and sets the RF/IF
optimization to Minimize Sweep Time.
To use the Spectrum Analysis preset (assuming that Spectrum Analysis is t he selected preset on the list of
Application Presets and Preset action is set to Recall selected preset):
RSA6100B Series & RSA5100A Series Printable Help29
Operating Your InstrumentPresets
1. Select File > More Presets > Application.
2. Set the measurement frequency using the front-panel knob or keypad.
3. Adjust the span to show the necessary detail.
Time-Frequency Analysis
The Time-Frequency Analysis application preset opens the following displays:
Time Overview: Shows a time-domain view of the analysis time ‘window’.
Spectrogram: Shows a three-dimensional view of the signal where the X-axis represents frequency,
the Y-axis represents time, and color represents amplitude.
Frequency vs. Time: This display's graph plots changes in frequency over time and allows you to
make marker measurements of settling times, frequency hops, and other frequency transients.
Spectrum: Shows a spectrum view of the signal. The only trace showing in the Spectrum graph
after selecting the Time-Frequency Analysis preset is the Spectrogram trace. This is the trace from
the Spectrogram display that is selected by the active marker. Stop acquisitions with the Run button
because its easier to work with stable results. In the Spectrogram display, move a marker up or down
to see the spectrum trace at various points in time.
Theanalysisperiodissetto5ms.
To use the Time-Frequency Analysis preset (assuming that Time-Frequency Analysis is the selected preset
on the list of Application Presets and Preset action is set to Recall selected preset):
1. Select File > More presets > Application.
2. When the preset's displays and settings have all been recalled and acquisitions are running, adjust the
center frequency and span to capture the signal of interest.
3. Set the Reference Level to place the peak of the signal approximately 0-10 dB down from the top of
the Spectrum graph.
4. If the signal is transient in nature, you might need to set a trigger to capture it. For more information
on triggering in the time and frequency domain, see Triggering
5. If the signal is transient in nature, you might need to s et a trigger to capture it. You will need to use the
oscilloscope triggering functions to capture the signal.
When the signal has been captured, the spectrogram shows an overview of frequency and amplitude
changes over time. To see frequency transients in greater detail, use the Frequency vs. Time display.
The Time-Frequency Analysis preset sets the analysis period to 5 ms. The Spectrum Span is 40 MHz. T he
RBW automatically selected for this Span is 300 kHz. For a 300 kHz RBW, the amount of data needed for
a single spectrum transform is 7.46 μs. A 5 ms Analysis Length yields 671 individual spectrum transforms,
each one forming one trace for the Spectrogram to display as horizontal colored lines. This preset scales
the Spectrogram time axis (vertical axis) to -2, which means that the Spectrogram has done two levels of
time compression, resulting in one visible line for each four transforms. This results in 167 lines in the
Spectrogram for each acquisition, each covering 29.84 μs.
(see page 392)
30RSA6100B Series & RSA5100A Series Printable Help
Operating Your InstrumentPresets
Creating User Presets
You can add your own presets to the list that appears in the User Presets dialog box. Configure the
analyzer as needed for your application an
C:\RSA5100A Files\User Presets. The name you give the filewillbeshownintheUserPresetslistonthe
Presets tab of the Options control panel. For instructions on how to save a Setup file, see Saving Data
(see page 413).
You can add y our own application presets t o the list that appears in the User Presets dialog box. Create a
Setup fi leandsaveacopyofittoC:\SignalVu Files\User Presets. The name you give the file will be
shown in the User Presets list. For instructions on how to save a Setu
NOTE. Prior versions of the analyzer software on RSA6100A Series instruments saved user-created
presets in the C:\RSA6100A Files\Application Presets folder. If you had any user- created setups in the
Application Presets folder before upgrading to this release, those files were automatically moved to the
User Presets folder during the upgrade process. There is no longer an Application Presets folder.
dcreateaSetupfile in C:\RSA6100B Files\User Presets or
p file, see Saving Data
(see page 413).
Configuring How Presets Are Recalled
Recalling Presets results in either of two actions. One action is to immediately execute a Preset. The
second action displays a list of Presets from which you select the Preset you want to recall. You specify
which action occurs when you recall a preset using the Presets tab on the Options control panel.
Configuring how a preset is recalled. To con figure how a preset is recalled:
1. Select File > More presets > Preset options This displays the Presets tab of the Options control panel.
2. Select the Preset type from the drop-down list that you want to configure. For each type listed thereare unique presets that appear in the Presets box.
3. Select the Preset action from the drop-down list.
4. If you select Recall selected preset from the Preset action list, click in the Presets list box on the
preset you wish to recall.
The selected preset, indicated by a tan background highlight, is the Preset that is recalled; on an
RSA5100A Series analyzer, press one of the Preset buttons on the front panel.
The selected preset, indicated by a tan background highlight, is the Preset that is recalled.
5. Set the measurement frequency using the front-panel knob or keypad.
6. Adjust the span to show the necessary detail.
RSA6100B Series & RSA5100A Series Printable Help31
Operating Your InstrumentSetting Options
Recalling a Preset
To recall the factory defaults Preset:
Press the Preset button on the front panel, select the Preset icon in the menu bar, or select File >Preset (Main).
To recall a named preset (an Application, DPX, or User Preset) from a menu:
To recall a named preset (an Application or User Preset) from a menu:
Select File
Preset type will be recalled (if Preset action is set to Recall named preset).
To r ecall a
Press the button on the front panel matching the preset type you want to recall. For example, to
recall a D
named preset from the front panel (RSA5100A Series only):
PX preset type, press the DPX button.
Setting Options
Menu Bar: Tools > Options
There are several settings you can change that are not related to measurement functions. The Option
settings control panel is used to change these settings.
>Morepresets>“Presettype”. ThePresetatthe top of the Presets list for the selected
32RSA6100B Series & RSA5100A Series Printable Help
Operating Your InstrumentSetting Options
Settings tab
Presets
Analysis Time
Save and ExportUse this tab to specify whether or not save files are named automatically and what
GPIBUse this tab
GPIBDo not use t
SecuritySelecting the Hide Sensitive readouts check box causes the instrument to replace
PrefsUse this
xxx
Description
Use this tab to
recalled and which preset to recall when the Preset button is selected.
Use this tab to specify the method used to automatically set the analysis and spectrum
offsets when the Time Zero Reference
informatio
Configuration control window in the TekScope application to set the instrument GPIB
address.
measurem
how markers should react when dragged.
configure Presets. You can specify the action to take when a preset is
(see page 357) is set to Trigger.
n is saved in acquisition data files.
to set the primary GPIB address for the instrument.
his tab to set the GPIB address for the instrument. Use the Utilities > GPIB
ent readouts with a string of asterisks.
tab to select different color schemes for the measurement graphs and specify
Presets
The Pre
Preset type. You can choose from the following preset types:
sets tab allows you to specify actions taken when you press the Preset button.
Main – There are two choices: Current: 2.4 and later and Original: V1.0-V2.3. Choose Current unless
you have existing tests or procedures that depend on values set by the older version of Preset.
Application – There are several application presets, depending on installed options. Each preset
selects a group of displays suited to the selected application type.
DPX – There are three DPX preset types: Swept, Real Time, and Zero Span.
er – These are setup files that have been saved by users in the folder C:\RSA6100B Files\User
Us
Presets or C:\RSA5100A Files\User Presets.
ser – These are setup files that have been saved by users in the folder C:\SignalVu Files\User Presets.
U
Preset action. The Preset action list allows you to specify what the instrument should do when you
request a preset. The choices are:
Recall selected preset – This action sets up the instrument to immediately recall the preset selected in
the Preset box without any further input from the user.
Show list – This action sets up the instrument to display a list box from which the user can select a
preset to recall.
Presets. This list box displays the available presets for the selected Preset type. The preset highlighted in
the list is the preset that will be recalled when Preset action is set to Recall selected preset.
Arrange. Use the Arrange buttons to change the order in which presets appear in the Presets dialog box
when Preset action is set to Show list.
RSA6100B Series & RSA5100A Series Printable Help33
Operating Your InstrumentSetting Options
Analysis Time
The Analysis Time tab in the Options control panel is used to specify the method used to automatically set
the analysis and spectrum offsets when the Time Zero Reference
available settings are:
Include trigger point – Selects an algorithm that uses the measurements to determine how far in
advance of the trigger to set the analysis offset. The analyzer tries to ensure that data about the trigger
point is inc
Startattriggerpoint(legacy)–Themethodusedby the instrument in prior versions, which sets the
Analysis O
point is included in the analyses. Use this method if your measurements or procedures depend on past
behavior of the Auto Analysis O ffset function.
luded in the analyses.
ffsettozerowhenpossible. Theanalyzertries to ensure that data following the trigger
(see page 357) is set to Trigger. The
Save and Export
The Save and Export tab allows you to specify whether or not files are saved with an automatically
generated name, and how much data is saved in an acquisition data file.
s. The Automatically increment filename/number function can automatically name saved files by
All file
appending a number to a base file name. Use this tab to enable/disable automatic naming of files. For
example, if Automatically Increment Filename Number is disabled, when you select Save from the File
menu, you will have to enter a name for the file.
Acquisition data files. This setting specifies whether saved data files include the entire acquisition record
ly the data for the analysis length (a subset of the acquisition record).
or on
TIQ acquisition data files. Specifies which data records to save. You can choose from the following:
Current acquisition: Saves the current acquisition.
rrent frame: If Fast Frame is enabled, saves only the current frame. The current frame is the
Cu
one most recently analyzed.
elected frames: If Fast Frame is enabled, saves the specified frames.
S
All in history: Saves all acquisition records in the history.
Save TIQ file now: Invokes the Save As dialog box with the Save as type drop-down list set to TIQ.
Prefs
The Prefs tab enables you to set properties that apply to all displays.
Color scheme. The Color scheme setting provides three color schemes for the measurement graphs. The
color scheme setting does not change the overall instrument application or Windows color scheme.
34RSA6100B Series & RSA5100A Series Printable Help
Operating Your InstrumentSetting Options
Thunderstorm – This scheme displays graphs in shades of blue. This provides a less vibrant color
scheme than the default setting.
Blizzard – This scheme displays graphs with a white background to save ink when printing.
Classic – The default setting. This scheme displays the graph area with a black background.
Markers snap to peaks when dragged. When selected, this s etting causes makers to automatically jump
eak
to the next p
marker to any point on the trace.
(see page 345) when you drag them. When this setting is deselected, you can drag a
RSA6100B Series & RSA5100A Series Printable Help35
Operating Your InstrumentSetting Options
36RSA6100B Series & RSA5100A Series Printable Help
Using the Measurement DisplaysSelecting Displays
Selecting Displays
Menu Bar: Setup > Displays
Application Toolbar: Displays
Use the Select Displays dialog to choose the displays that appear on the screen.
To select displays:
1. Press the Displays button or s elect Setup > Displays.
2. Select Setup > Displays or click the displays icon..
3. Select one of the choices under Folders. The folder chosen determines the choices available in
Available displays.
4. Double-click the desired display in the Available displays box or select the desired display andclick Add.
5. Click OK.
Interactions Between Displays
Different displays can require different settings, for example acquisition b andwidth, analysis length, or
resolution bandwidth, to achieve optimum results. The instrument automatically adjusts some settings
RSA6100B Series & RSA5100A Series Printable Help37
Using the Measurement DisplaysSelecting Displays
to optimize them for the selected display. The check mark indicator in the upper, left-hand corner of the
display indicates the display for which the acquisition hardware is optimized. Depending on instrument
settings, som
e displays might stop displaying results if they are not the selected display.
38RSA6100B Series & RSA5100A Series Printable Help
Taking MeasurementsAvailable Measurements
Available Measurements
The automatic measurements available include RF power measurements, analog modulation
measurements, digital modulation measurements, and pulse measurements.
Power Measurements
MeasurementDescription
Channel PowerThe total RF power in the selected channel (located in the ACPR display).
Adjacent Channel Power RatioMeasure of the signal power leaking from the main channel into adjacent channels.
Multi-Carrier Power RatioThe ratio of the signal power in the reference channel or group of channels to the power
in adjacent channels.
Peak/Avg RatioRatio of the peak power in the transmitted signal to the average power in the transmitted
signal (located in the CCDF display).
CCDFThe Complementary Cumulative Distribution Function (CCDF). CCDF shows how much
time a signal spends at or above a given power level relative to the average power of
a measured signal.
xxx
RSA6100B Series & RSA5100A Series Printable Help39
Taking MeasurementsAvailable Measurements
Digital Modulation Measurements
Measurements for all modulation types except nFSK, C4FM, OQPSK and SOQPSK
MeasurementDescription
EVM
Phase Error
Mag Error
MER (RMS)The MER is defined as the ratio of I/Q signal power to I/Q noise power; the result is
IQ Origin OffsetThe magnitude of the DC offset of the signal measured at the symbol times. It indicates
Frequency Error
Gain ImbalanceThe gain difference between the I and Q channels in the signal generation path.
Quadrature ErrorThe orthogonal error between the I and Q channels. The error shows the phase
Rho
xxx
The normalized RMS value of the error vector between the measured signal and the ideal
reference signal over the analysis length. The EVM is generally measured on symbol or
chip instants and is reported in units of percent and dB. EVM is usually measured after
best-fit estimates of the frequency error and a fixed phase offset have been removed.
These estimates are made over the analysis length. Displays RMS and Peak values with
location of Peak value.
The RMS phase difference between the measured signal and the ideal reference signal.
Displays RMS and Peak values with location of Peak value.
The RMS magnitude difference between the measured signal and the reference signal
magnitude. Displays RMS and Peak values with location of Peak value.
indicated in dB.
the magnitude of the carrier feed-through signal.
The frequency difference between the measured carrier frequency of the signal and the
user-selected center frequency of the instrument.
Constellations with gain imbalance show a pattern with a w idth that is different form
height.
difference between I and Q channels away from the ideal 90 degrees expected from the
perfect I/Q modulation. Not valid for BPSK modulation type.
The normalized correlated power of the measured signal and the ideal reference signal.
Like EVM, Rho is a measure of modulation quality. The value of Rho is less than 1 in all
practical cases and is equal to 1 for a perfect signal measured in a perfect receiver.
40RSA6100B Series & RSA5100A Series Printable Help
Taking MeasurementsAvailable Measurements
Measurements for OQPSK and SOQPSK modulation types
MeasurementDescription
EVM
Offset EVMOffset EVM is like EVM except for a difference in the time alignment of the I and Q
Phase Error
Mag Error
MER (RMS)The MER is defined as the ratio of I/Q signal power to I/Q noise power; the result is
in Offset
IQ Orig
ncy Error
Freque
Gain ImbalanceThe gain difference between the I and Q channels in the signal generation path.
Quadrature ErrorThe orthogonal error between the I and Q channels. The error shows the phase
Rho
xxx
The normalized RMS value of the error vector between the measured signal and the ideal
reference sig
nal over the analysis length. The EVM is generally measured on symbol or
chip instants and is reported in units of percent and dB. EVM is usually measured after
best-fit estimates of the frequency error and a fixed phase offset have been removed.
These estima
tes are made over the analysis length. Displays RMS and Peak values with
location of Peak value.
samples. For EVM, I and Q samples are collected at the same time, for every symbol
decision po
int (twice the symbol rate for offset modulations). For Offset EVM, the I and Q
symbol decision points are time-aligned before collecting the I and Q samples. In this
case, one I and one Q sample is collected for each symbol (half as many samples as the
same numbe
The RMS pha
r of symbols for (non-offset) EVM.
se difference between the measured signal and the ideal reference signal.
Displays RMS and Peak values with location of Peak value.
The RMS magnitude difference between the measured signal and the reference signal
magnitude. Displays RMS and Peak values with location of Peak value.
ed in dB.
indicat
The mag
nitude of the DC offset of the signal measured at the symbol times. It indicates
the magnitude of the carrier feed-through signal.
The frequency difference between the measured carrier frequency of the signal and the
user-selected center frequency of the instrument.
ellations with gain imbalance show a pattern with a width that is different form
Const
height.
difference between I and Q channels away from the ideal 90 degrees expected from the
fect I/Q modulation. Not valid for BPSK modulation type.
per
normalized correlated power of the measured signal and the ideal reference signal.
The
Like EVM, Rho is a measure of modulation quality. The value of Rho is less than 1 in all
practical cases and is equal to 1 for a perfect signal measured in a perfect receiver.
RSA6100B Series & RSA5100A Series Printable Help41
Taking MeasurementsAvailable Measurements
Measurements for nFSK modulation types
MeasurementDescription
Peak FSK errPeak value of the frequency deviation error at the symbol point.
RMS FSK ErrRMS value of the frequency deviation error at the symbol point.
Peak Mag Err
The Peak magnitude difference between the measured signal and the reference signal
magnitude.
RMS Mag ErrThe RMS magn
itude difference between the measured signal and the reference signal
magnitude.
Freq Error
The frequency difference between the measured carrier frequency of the signal and the
user-selected center frequency of the instrument.
Freq Deviation
Frequency distance from the center frequency at the symbol point.
Symbol Rate ErrorThis compares the user-entered symbol rate to the instrument calculated symbol rate of
yzed signal.
uto-symbol rate, the instrument calculates the symbol rate of the signal and
Symbol R
ate
the anal
When in A
the instrument calculates the error between the user entered value and the instrument
calculated value.
xxx
Measurements for C4FM modulation type
MeasurementDescription
RMS Error MagnitudeRMS value of the frequency deviation error at the symbol point.
Carrier Frequency ErrorFrequency difference between averaged signal frequency and the center frequency.
Deviation
Length
xxx
Frequency distance from the center frequency at the symbol point.
Number of symbols in the analysis area.
Analog Modulation Measurements
asurements for AM modulation
Me
asurement
Me
+AMPositive peak AM value.
-AMNegative peak AM value.
otal AM
T
xxx
Measurements for FM modulation
MeasurementDescription
+Pk
–Pk
RMSRMS value of the frequency deviation.
Pk-Pk/2Peak-to-peak frequency deviation divided by 2.
Pk-Pk
xxx
scription
De
otal AM value, which is equal to the peak-peak AM value divided by 2.
T
Positive peak frequency deviation.
Negative peak frequency deviation.
Peak-to-peak frequency deviation.
42RSA6100B Series & RSA5100A Series Printable Help
Taking MeasurementsAvailable Measurements
Measurements for PM modulation
MeasurementDescription
+PkPositive peak phase deviation.
–PkNegative peak
RMSRMS value of t
phase deviation.
he phase deviation.
Pk-PkPeak-to-peak phase deviation.
xxx
Pulse Measurements
MeasurementDescription
Average ON Power
Peak PowerMaximum power during pulse on.
Average Transmitted PowerThe average power transmitted, including both the time the pulse is on and the time
Pulse Width
Rise Time
Fall Time
Repetition Interval
Repetition Rate
Duty Factor (%)The ratio of the width to the pulse period, expressed as a percentage.
Duty Factor (Ratio)The ratio of the pulse width to the pulse period.
RippleRipple is the peak-to-peak ripple on the pulse top. It does not include any preshoot,
Ripple dBThe Ripple measurement expressed in dB.
Droop
Droop dBThe Droop measurement expressed in dB.
OvershootThe amount by which the signal exceeds the 100% level on the pulse rising edge. Units
Overshoot dBThe Overshoot measurement expressed in dB.
Pulse-Pulse Phase DifferenceThe phase difference between the selected pulse and the first pulse in the analysis
The average power transmitted during pulse on.
it is off, and all transition times.
The time from the rising edge to the falling edge at the –3 dB / –6 dB level (50%) of the
user selected 100% level. Level is user selectable for Volts or Watts.
The time required for a signal to rise from 10% to 90% (or 20% to 80%) of the user
selected 100% level.
The time required for a signal to fall from 90% to 10% (or 80% to 20%) of the user
selected 100% level.
The time from a pulse rising edge to the next pulse rising edge.
The inverse of repetition interval.
overshoot, or undershoot. By default, the first 25% and the last 25% of the pulse top is
excluded from this measurement to eliminate distortions caused by these portions of
the pulse.
If the Amplitude units selected in the Amplitude panel (affects all amplitude measurements
for the analyzer) are linear, the Ripple results will be in %Volts. For log units, the Ripple
results will be in %Watts. The default for the general Units control is dBm, so the Ripple
results default is %Watts.
See also Ripple
(see page 471).
Droop is the power difference between the beginning and the end of the pulse On time. A
straight-line best fit is used to represent the top of the pulse. T he result is a percentage
referenced to the Average ON Power.
are %Watts or %Volts.
window. The instantaneous phase is measured at a user-adjustable time following the
rising edge of each pulse.
RSA6100B Series & RSA5100A Series Printable Help43
Taking MeasurementsAvailable Measurements
MeasurementDescription
Pulse-Pulse Freq DifferenceThe difference between the frequency of the current pulse and frequency of the previous
pulse. The ins
rising edge of each pulse.
RMS Freq ErrorThe RMS Frequency Error measurement is the RMS average of the Freq Error vs. Time
trace, computed over the Measurement Time.
Max Freq Error
The maximum frequency error is the difference between the measured carrier frequency
of the signa
RMS Phase Er
ror
The RMS Phas
computed over the Measurement Time.
Max Phase E
rror
The phase is measured at each point during the pulse's ON time. The phase error for
each point is the difference between the measured phase value and the calculated ideal
phase val
the largest error in the positive direction and the largest in the negative direction are
determined. Whichever of these two values has the greater absolute value is designated
the Max Ph
Freq Deviation
The Freq
minimum measured values of the signal frequency during the Measurement Time.
Phase De
viation
The Phase Deviation is the difference between the maximum and minimum Phase values
measured during the ON time of a pulse.
Impulse Response Amplitude
Impulse Response Time
Time
xxx
The difference in dB between the levels of the main lobe and highest side lobe.
The difference in time between the main lobe and highest side lobe.
This is the time in seconds relative to the time reference point in the first acquisition
rd in the data set.
reco
tantaneous frequency is measured at a user-adjustable time following the
l and the user-selected center frequency of the analyzer.
e Error measurement is the RMS average of the Phase vs Time trace,
ue. After the phase error is calculated for all points in the acquisition record,
ase Error.
uency Deviation measurement is the difference between the maximum and
44RSA6100B Series & RSA5100A Series Printable Help
General Signal ViewingOverview
Overview
The displays in the General Signal Viewing folder (Displays > Folders > General Signal Viewing) are:
Amplitude vs Time
DPX Spectrum
Frequency vs Time
Phase vs Tim
RF I & Q vs Time
Spectrogram
Spectrum
Time Overview
These displays provide extensive time-correlated multi-domain views that connect problems in time,
frequency, phase and amplitude for enabling you to more quickly understand cause and effect when
troubleshooting.
DPX Primer
With the DPX display you can detect and accurately measure transients as brief as 3.7 µs (RSA6100B
Series and RSA5100A Series with Option 200). The instrument computes up to 292,000 spectrums per
second (up to 48,833 without Option 200 in the RSA5100A Series) of the digitized input signal. Then it
displays all these spectrums as a color-graded bitmap that reveals low-amplitude signals beneath stronger
signals sharing the same frequency at different times.
The strong signal in the DPX spectrum graph, showninFigure1,isarepeatingpulseatafixed frequency.
There is also a lower-power CW signal that steps very quickly through the same span. During the pulse's
time, the power of the two signals is additive, resulting in nearly undetectable differences in the pulse
on
envelope shape. But during the time the pulse is off, the sweeping signal is detected and shown in its true
form. Both signals are visible in the bitmap because at least one full cycle of their activities occurs
within a single DPX display update.
e
RSA6100B Series & RSA5100A Series Printable Help45
General Signal ViewingDPX Primer
Figure 1
Compare the display of a traditional swept spectrum analyzer (Figure 2) and that of a real-time signal
analyzer with a DPX display (Figure 3). The signal captured is a typical WLAN interchange between
a nearby PC and a more-distant network access point (AP). The laptop signal is nearly 30 dB stronger
than the AP's signal because it is closer to the measuring antenna.
Figure 2
46RSA6100B Series & RSA5100A Series Printable Help
General Signal ViewingDPX Primer
Figure 3
The traditional swept spectrum analyzer display, Figure 2, uses line traces that can show only one level f or
each frequency point, representing the largest, the smallest or the average power. After many sweeps, the
Max Hold trace shows a rough envelope of the stronger laptop signal. +Peak detection was selected for the
other trace in an attempt to capture the weaker but more frequent AP signal, but the bursts are very brief,
so the likelihood of seeing one in any particular sweep is small. It will also take a long time to statistically
capture
the entire spectrum of a bursted signal due to the architecture of the swept spectrum analysis.
The DPX display, Figure 3, reveals much more insight on the same signal. Since it is a bitmap image
d o f a line trace, you can distinguish many different signals occurring within each update period
instea
and/or different version of the same signal varying over time. The heavy band running straight across the
lower third of the graph is the noise background when neither the laptop nor the AP is transmitting. The red
lump of energy in the middle is the ON shape of the AP signal. Finally, the more delicate spectrum above
the others is the laptop transmissions. In the color scheme used for this demonstration (“Temperature”),
the hot red color indicates a signal that is m uch more frequent than signals shown in cooler colors. The
op signal, in yellow, green and blue, has higher amplitude but doesn't occur n early as often as the AP
lapt
transmissions because the laptop was downloading a file when this screen capture was taken.
How DPX Works
This section explains how DPX displays are created. The input RF signal is conditioned and
down-converted as usual for a signal analyzer, then d igitized. The digitized data is sent through an FPGA
that computes very fast spectral transforms, and the resulting frequency-domain waveforms are rasterized
to create the bitmaps.
The DPX bitmap that you see on screen is composed of pixels representing x, y, and z values for frequency,
amplitude, and Density ( RSA5100A Series instruments without Option 200 provide hit count as the z-axis
value in place of Density). A multi-stage process, shown in Figures 4a - 4d, creates this bitmap, starting
with analog-to-digital conversion of the input signal.
RSA6100B Series & RSA5100A Series Printable Help47
General Signal ViewingDPX Primer
Simplified Flow of Multi-stage Processing from RF Input Through to Spectrum Processing:
Figure 4a. RF signals are downconverted and sampled into a continuous data stream.
Figure 4b. Samples are segmented into data records for FFT processing based on the selected resolution bandwidth.
Figure 4c. Data records are processed i
n the DPX transform engine
Figure 4d. Overlapping the FFTs shortens the minimum event duration required for 100% probability of intercept.
Collecting spectral d ata. Sampling and digitization is continuous. The digitized data stream is chopped
into data records whose length is based on the desired resolution bandwidth (RBW). An additional
requirement is placed on FFT length by the desired number of points in a trace (RSA6100B Series and
RSA5000A Series with Option 200). Table 1 shows this relationship and the FFT length is reported in
the display if desired. Then the DPX transform e
ngine performs a discrete Fourier transform on each
record, continually producing spectral waveforms.
RF signals are downconverted and sampled into
a continuous data stream.
Samples are segmented into data records for FFT processing based on the selected resolution
bandwidth.
Data records are processed in the DPX transform engine.
Overlapped processing is u sed to improve minimum event duration performance.
Table 1: Minimum FFT length versus trace length – independent of span and RBW (RSA6100B Series and
RSA5100A Series with Option 200)
Trace length (points)Minimum FFT length
8011,024
2,4014,096
48RSA6100B Series & RSA5100A Series Printable Help
General Signal ViewingDPX Primer
Table 1: Minimum FFT length versus trace length – independent of span and RBW (RSA6100B Series and
RSA5100A Series with Option 200) (cont.)
Trace length (points)Minimum FFT length
4,0018,192
10,40116,384
xxx
As long as spectral transforms are performed faster than the acquisition data records arrive, the transforms
can overlap each other in time, so no events are missed in between. Minimum event length for guaranteed
capture d epends on the length of the data records being transformed. An event must last through two
consecutive data records in order for its amplitude to be accurately measured. Shorter events are detected
and visi
ble on screen, but may be attenuated. The DPX Spectrum RBW setting determines the data
record length; narrow RBW filters have a longer time constant than wide RBW filters. This longer time
constant requires longer FFTs, reducing the transform rate. Additional detail on m inimum signal duration
is provided in Guaranteed Capture of Fast Events
(see page 55).
The spectral waveforms are plotted onto a grid of counting cells called the “bitmap database”. The number
held by each database cell is the z-axis count. For simplicity, the small example grid used here in Figure 6
is 11x10, so our spectral waveforms will each contain 11 points. A waveform contains one (y) amplitude
value f or each (x) frequency. As waveforms are plotted to the grid, the cells increment their values each
they receive a waveform point.
time
Figure 5. Example 3-D Bitmap Database after 1 (left) and 9 (right) updates. Note that each column contains
the same total number of “hits”.
The grid on the left shows what the database cells might contain after a single spectrum is plotted into it.
Blank cells contain the value zero, meaning that no points from a spectrum have fallen into them yet.
The grid on the right shows values that our simplified database might contain after an additional eight
spectral transforms have been performed and their results stored in the cells. One of the nine spectrums
happened to be computed as a time during which the signal was absent, as you can see by the string of “1”
occurrence counts at the noise floor.
Frame updates. The maximum rate for performing the variable-length frequency transforms that produce
those waveforms can be g reater than 292,000 per second. Measurement settings that slow this transform
rate include narrowing the RBW and increasing the number of points for the line traces available in the
DPX display along with the bitmap. Even at their slowest, spectral transforms are performed orders of
magnitude faster than a physical display can respond, and also too fast for humans to see, so there's no
RSA6100B Series & RSA5100A Series Printable Help49
General Signal ViewingDPX Primer
need to update the screen or measurements at this rate. Instead, the grid collects thousands of waveforms
into “frames”, each covering about 50 milliseconds (ms). A 50 ms frame contains the counts from up to
14,600 wavefo
rms. After each frame's waveforms have been mapped into the grid, the cell occurrence
counts are converted to colors and written to the DPX bitmap, resulting in a bitmap update rate of
around 20 per second.
Frame length sets the time resolution for DPX measurements. If the bitmap shows that a -10 dBm
signal at 72.3 MHz was present for 10% of one frame's duration (5 m s out of 50 ms), it isn't possible to
determine just from the DPX d isplay whether the actual signal contained a single 5 ms pulse, one hundred
50 microsecond (μs) pulses, or something in between. For this information, you need to examine the
spectral details of the signal or use another display with finer time resolution, such as Frequency vs.
Time or Amp
litude vs. Time.
Converting occurrence counts to color. About 20 times per second, the grid values are transferred to the
next process step, in which the z-axis values are mapped to pixel colors in the visible bitmap, turning
data into information (Figure 6). In this example, warmer colors (red, orange, yellow) indicate more
occurrences. The color palette is user-selectable, but for now we will assume the default “temperature”
e.
palett
Number
xxx
of Occurrences
0black
1blue
2light
3
4green blue
5
6yellow
7
8red orange
9re
gure 6. Example Color-mapping algorithm
Fi
Color
cyan
gree
ora
blue
n
nge
d
The result of coloring the database cells, Figure 7, according to the number of times they were written into
by the nine spectrums, one per pixel on the screen, creates the DPX displays.
50RSA6100B Series & RSA5100A Series Printable Help
General Signal ViewingDPX Primer
Figure 7. Color-coded low-resolution example (left) and a real DPX display (right).
In addition to the choice of palette, there are z-axis scaling adjustments for Maximum, Minimum, and
Curve. Maximum sets the occurrence value that will be mapped to the highest color in the palette.
Minimum
deep red and the lowest is dark blue. Occurrence values less than the selected Minimum are represented
with black pixels, while pixels that exceed the selected Maximum are red in hue but somewhat transparent.
Values between Maximum and Minimum are represented by the other colors of the palette.
sets the occurrence value for the lowest color. In the “temperature” palette, the highest color is
Adjusting the Minimum above the black default allows you to concentrate most of your color resolution
over a small range of medium or higher occurrence rates to visually discriminate between different signals
that have nearly equal probability values.
To see why adjustable color scaling is useful compare Figures 8 and 9. On the Scale tab, the Max control is
set to 100% in Figure 8. The range of colors now covers the full z-axis range of densities from 0 to 100%.
The signals used to create this bitmap are fairly diffused in both frequency and amplitude, so most pixels
low occurrence counts o r density values and the upper half of the color palette is unused.
have
Figure 8. DPX spectrum bitmap with default color scale settings.
RSA6100B Series & RSA5100A Series Printable Help51
General Signal ViewingDPX Primer
When the Auto Color button is selected, the Maximum control's value is set to the highest pixel value
in the current bitmap, shown in Figure 9. Now none of the available colors remain unused. The entire
palette is map
visual resolution for low densities. Selecting the Autoscale button in the DPX display scales all three
axes based on current results.
Figure 9. The Auto Color function optimizes the color scale settings.
ped to the occurrence values present at the time the button is selected, providing better
Color Mapping Curves
The mapping between z-axis values and color does not have to be linear. The Curve control lets you
choose the s hape of the mapping equation. A Curve setting of 1 selects the straight-line relationship.
Higher Curve numbers pull the curve upwards and to the left, concentrating color resolution on lower
densities. Settings less than 1 invert the curve, moving the focus of the color range towards higher density
values. Figure 10 shows the mapping curves.
Figure 10. Representative color mapping curves for the “Temperature” palette.
Using the same signal shown in Figures 8 and 9, the impact of the Curve control can be observed. With
the Curve control set to 1 in the Scale tab, shown in Figure 11, the mapping between color and density is
linear, so the colors spread evenly across the full density range. The color distribution is visible in the
colored palette illustration to the left of the Curve control in the Settings panel.
52RSA6100B Series & RSA5100A Series Printable Help
General Signal ViewingDPX Primer
Figure 11. Ov
When the Cur
the density range, and only the dark blues are assigned to densities below 50%. Note the difference in
the palette illustration.
Figure 12. Adjusting to values less than 1, increases the contrast for viewing events in the top half of the selected
density range.
In Figure 13, the Curve control is increased to 3. The majority of colors shifts to the lower half of the
density scale, but various shades of orange and red are still available for densities above 50%.
er a narrow Signal Density range, the color curve is set to 1.
ve control is set to 0.5, as shown in Figure 12, the best color resolution is in the upper half of
Figure 13. For color curve settings greater than 1, better contrast is provided for events near the low end of the
density range.
Swept DPX
DPX Spectrum is not limited in span by its real-time bandwidth. Like the regular Spectrum display, DPX
Spectrum steps through multiple real-time frequency segments, building a wide-span display with line
traces and the bitmap (RSA6100B Series and RSA5100A Series with Option 200). See Figure 14.
RSA6100B Series & RSA5100A Series Printable Help53
General Signal ViewingDPX Primer
Figure 14. Off-air ambient signals over a 1 GHz span in the swept DPX display.
The analyzer “dwells” in each frequency segment for one or more DPX frames, each containing the results
of up to 14,
sweep for up to 100 seconds before moving to the next step. While dwelling in a segment, the probability
of intercept for signals within that frequency band is the same as in normal, real-time spans: 100% capture
of events as short as 10.3 μsec.
A full pixel bitmap is created for every segment and compressed horizontally to the number of columns
needed for displaying the frequency segment. Compression is done by averaging pixel densities o f the
points being combined together. The final swept bitmap contains a representation of the same pixel bitmap
resolution, just like the non-swept bitmaps. Line traces are also created in full for each segment, and then
horizo
600 spectral transforms. Dwell time is adjustable, so you can monitor each segment of the
ntally compressed to the user-selected numberoftracepointsforthefullspan.
A complex algorithm for determining the number and width of each frequency segment has been
mented. The variables in the equation include user-adjustable control settings like Span, RBW, and
imple
number of trace points, RF and IF optimization, and Acquisition BW. Installed hardware options also can
affect the span segmentation. The number of segments ranges from 10 to 50 for each 1 GHz in a sweep.
A helpful piece of information for operators is the actual Acquisition Bandwidth used for capturing each
segment. “Acq BW” is shown in the Acquire control panel on the Sampling Parameters tab. Acq BW is
typically set automatically by the instrument, based on the needs of all the open displays, but can also be
set manually. In either case, the displayed bandwidth is used for every frequency segment in the swept
DPX display, though in practice, the displayed portion of the segment is somewhat narrower than the
tual Acquisition BW, for performance reasons.
ac
The entire instrument frequency range of many GHz can be covered in a DPX sweep. The Dwell Time
ontrol sets the amount of time DPX spends in each segment. This control, circled in Figure 15, can be
c
set between 50 ms and 100 seconds.
Figure 15. During swept DPX operation, the Dwell time control adjusts the observation time of each frequency
segment used to construct the composite DPX display.
54RSA6100B Series & RSA5100A Series Printable Help
General Signal ViewingDPX Primer
Guaranteed Capture of Fast Events
The main reason that swept-tuned and step-tuned spectrum analyzers can't provide 100% Probability of
Intercept, POI, for a signal that isn't continuously present is that they spend only a short period of time
tuned to each segment of their frequency span during each sweep. If something happens in any part of
the span othe
r than where it is tuned at that instant, that event will not be detected or displayed. There
is a l so a period of time between sweeps, retrace time, during which the analyzer is not paying attention
to the input signal. FFT-based analyzers, including vector signal analyzers, also miss signals during
the time between acquisitions. Their POI depends on a combination of factors including span, number
of FFT points, acquisition time, memory read/write time, and signal processing speed. Vector analyzers
process information sequentially, so when read/write from data and processing is occurring, data is not
being acqu
ired.
RSAs, on the other hand, capture data across all frequencies within their real-time span during every
acquisit
ion. With Tektronix' exclusive Frequency Mask trigger and DPX Density trigger, POI increases to
100%, insuring capture of any spectral event matching the trigger definition. When operating in free run as
a simple signal analyzer, the RSA has a POI similar to other FFT-based analyzers, with gaps between
each acquisition. Processing is done concurrent with the acquisitions.
Guaranteed Capture in DPX Real-Time Spans
The DPX display captures any signal that is at least 10.3 microseconds long (RSA6100B Series and
RSA5000A Series with Option 200) and within the real-time bandwidth. This performance is possible
use the RSA computes up to 292,000 spectrum transforms per second. The faster the spectrum updates,
beca
the shorter the time between acquisitions and the greater the probability that any signal will be detected.
le 1 shows the specified minimum signal duration (MSD) for 100% probability of intercept under
Tab
various combinations of Span and RBW in DPX for a representative RSA model. As you can see, MSD is
affected by multiple factors.
Table 2: Minimum signal duration specifications for RSA6100B series signal analyzers
Span
(MHz)
110100001110243.7
11010001101024292,9695.8
1103003672048146,48414.8
1101001100409673,24237.6
1103036671638418,311134.6
110205500327689,155229.2
xxx
1
With Options 110 under various combinations of control parameters.
RBW
(kHz)
Span/RBW
Ratio
FFT
LengthSpectrum/sec
1
MSD for
100% POI (μs)
To demonstrate the POI in action, a challenging bi-stable signal is used. A CW sinusoid sits at 2.4453 GHz
most of the time, but every 1.28 seconds, its frequency changes for about 100 μs before returning to
normal. The duty factor of this transient is less than 0.01%.
Figure 16 shows a swept analyzer set up for a 5-second sweep of its MaxHold trace. It shows that there is
something occurring around the signal. This sweep rate was empirically determined to be the optimum rate
RSA6100B Series & RSA5100A Series Printable Help55
General Signal ViewingDPX Primer
for reliable capture of this signal in the shortest time. Faster sweep times can reduce the probability of
intercept and result in fewer intersections of the sweep with the signal transient.
Figure 16. Swept spectrum display of the infrequent transient.
The DPX display shown in Figure 17 shows the exact same event, also captured over a 5 second period. A
lot more information can be discovered about the transient. It is obvious at first glance that the signal is
hopping by about 3 MHz, with 1.2 MHz of frequency overshoot on transitions
Figure 17. The DPX spectrum display after 5 seconds. The MaxHold trace is cyan.
56RSA6100B Series & RSA5100A Series Printable Help
General Signal ViewingDPX Primer
Guaranteed Capture in DPX Swept Spans
Probability of intercept (POI) for signals within a single segment, while DPX is dwelling in that segment,
is the same as for non-swept DPX operation (POI = 100% for e vents as brief as 10.3 microseconds).
But just as in traditional swept analyzers, during the time the acquisition is tuned to any one segment,
the analyzer
other than the current one is zero. Because of the wide real-time bandwidth, the number of segments
needed to cover the span is much less than for swept analyzers, so the overall probability of intercept is
significantly better for DPX sweeps.
Another factor affecting POI is number of trace points. The bitmap is always 801 points wide, but the
line traces allow user selection for number of points. 801 is the default and the other choices are 2401,
4001, and 10401. Frequency transforms for traces containing more than 801 points take longer, and this
lower waveform update rate increases the minimum signal duration proportionally. This caution applies
for swept
is not monitoring signals in any of the other segments, so probability of capture in segments
and non-swept operation. The trace length control is on the Prefs tab in the DPX control panel.
DPX Density Measurements
“Density” is a measure of the a mount of time during a defined measurement period during which signals
are present within a particular area of the DPX Spec trum bitmap. A clean CW tone gives a 100% reading,
while a pulse that is on for one microsecond out of every millisecond reads 0.1%. This section describes
how density is computed from hit counts.
If we plot 41 more waveforms into the example grid we used previously in Figure 6 (in addition to the nine
we already plotted), each column ends with a total of 50 hits (Figure 18). The density for any one cell in a
column is its own count value d ivided by 50, expressed in percent as shown in Figure 19. The math is
y simple: a cell with 24 counts has a 48% density. In practice, instead of batches of 50 waveforms, we
ver
collect a frame of thousands of waveforms before each update to the density bitmap.
Figure 18. Grid showing cell counts after 50 waveforms. For each column, the sum of z-axis values is 50.
RSA6100B Series & RSA5100A Series Printable Help57
General Signal ViewingDPX Primer
Figure 19. Grid after converting occurrence counts to percent density values. The sums of the cell density
measurements within each column are all 100%.
Measuri
Hit counts are cleared after every frame update, as long as Persistence is not turned on. The density
value fo
Markers can be used to see the Density value for one or more individual points on the screen, enabling
measurements of the signal density at any interesting point in the DPX display.
In Figure 20, Wireless LAN signals are analyzed in the presence of a Bluetooth radio signal in the 2.4 GHz
ISM band.
Figure 20. DPX display of WLAN and Bluetooth signals, with a marker on the highest signal.
ng Density with Markers
r any pixel is simply the percent of time it was occupied during the most recent 50 ms frame.
The “Marker to Peak” function was used to find the peak signal recorded in the display. The marker
readout in the upper left corner of Figure 20 shows the Density, Amplitude, and Frequency for the
pixel you selected with the marker. By adding additional markers, you can measure the signal density
differences between multiple signals of interest.
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Marker Peak Search in the DPX Bitmap
Markers on the DPX bitmap can search for peaks, similar to marker peak searching on spectrum line
traces. For a human, it is pretty easy to discern “signals” in the bitmap picture. Your brain intuitively
identifies strings of contiguous bright pixels. This isn't so easy for a computer. The first thing the RSA
must do for an
through these density peaks for the amplitude peaks you want to find.
y peak search is analyze pixel density values to identify apparent signals. Then it can sift
Z-axis dens
ity values for the pixels in each column of the bitmap are internally converted into histograms
to find density peaks indicating the presence of signals. Table 2 shows the five middle columns from
the example grid we used to illustrate density measurements in a previous section (Figure 19). The
density values for each pixel in the middle, highlighted column are plotted on the y axis in the bar chart in
Figure 21. The bar chart x axis is bitmap row number, numbering from the top of the table.
Table 3: Bitmap section showing density values.
0%0%0%0%0%
0%0%8%0%0%
0%0%12%0%0%
0%0%26%0%0%
0%0%36%0%0%
0%2%6%2%0%
4%8%0%8%0%
86%82%4%76%12%
10%8%6%14%86%
0%0%2%0%2%
xxx
Figure 21. Bar chart of the density values in the bolded column of Table 2.
Assume that Density Threshold is set to 5% and Density Excursion to 5% also. Starting with x=1 in the
bar chart, test each bar against the threshold. The threshold criteria is met at x=2. Keep testing until you
RSA6100B Series & RSA5100A Series Printable Help59
General Signal ViewingDPX Primer
find a bar that is shorter than the previous bar by at least the Excursion setting. In this case it is x=6. This
tells us that a “signal” covers rows 2 through 5. Its density peak is at row 5.
Now you can look for another peak. Continue looking at bars to the right and you will find a density
value at row 9 that meets the threshold criteria, but since there are no bars to the right of it that meet the
excursion cr
had1%density,thenrow9wouldbeadensitypeak.
iteria, we can't declare row 9 a signal because it fails to meet the excursion criteria. If row 1
Once densit
When the Peak button is selected, the analyzer checks the histograms of every column in the bitmap and
finds the density peak with the highest amplitude. The amplitude search has its own versions of Threshold
and Excursion settings, but in dBm and dB units. When Next Peak Down command is given, the search
will scan inside the current column for the next density peak. Next Peak Right examines each column to
the right of the current marker location to locate density peaks that also meet the amplitude peak criteria.
To demonstrate the value of marker peak search in the DPX bitmap, we will use the time-multiplexed
signals showing multiple amplitude levels from an example earlier in this manual. The Peak button
and its m
density peak of highest amplitude in the bitmap.
Figure 22. The marker was positioned by selecting the Peak button. Density, frequency, and amplitude measurements
at the marker are displayed in the upper left corner of the graph.
y peaks are found for all columns in the bitmap, we can start looking for the amplitude peaks.
enu equivalent place the active marker on the peak signal in Figure 22. The peak signal is the
The Marker Toolbar, at the bottom of Figure 22, allows easy navigation of peak signals (Peak Left, PeakRight, Next Peak Up,orNext Peak Down). Selecting the arrow keys enables the marker to search for
amplitude/density peaks at other frequencies, while the Next Peak Up and Next Peak Down arrows
nable the marker to search for other high-density points at the same frequency.
e
In the Define Peaks tab of the Define Markers control panel, Figure 24, you can adjust the density threshold
nd excursion controls to modify search behavior. The amplitude threshold and excursion controls also
a
apply to DPX marker searches. Smoothing keeps the marker from finding multiple peaks within the same
apparent signal by averaging an adjustable number of pixel densities together, but it does not affect the
single-pixel measurement readout displayed by the marker.
60RSA6100B Series & RSA5100A Series Printable Help
General Signal ViewingDPX Primer
Figure 24. Amplitude and Signal Density controls can be adjusted to define Peak search behavior.
Density Measurements over an Adjustable Area (“The Box”)
The density for a single pixel is its ratio of actual hits vs. possible hits over a defined time period, and
markers display these density values. For measuring density over an area larger than one pixel, the DPX
display (
resize and drag around in the DPX display with your mouse or finger.
RSA6100B Series and RSA5000A Series with Option 200) includes a measurement box you can
If you co
density of this area would be the sum of the included pixels' density values. For example, if the box was
three pixels tall and the density values for these pixels were 4, 2, and 7% respectively, the overall density
for the three-pixel area would be 13%. Imagine a box one pixel wide and as tall as the graph. Assume that
the input signal's amplitude was such that all hits fell at or near the vertical center of the screen. Since
100% of the waveforms written to the bitmap passed through the box, the density for the box is 100%.
When you widen the box to cover a broader range of frequencies, software computes the density sum for
the included pixels in each column inside the box. The aggregate density value for this box is the average
den
result, there must not be any hits above the top edge of the box or below its bottom edge. In other words,
every waveform drawn across the graph entere d the box through its left side and exited the box through its
right side, with no excursions out the top or bottom. Figure 24 demonstrates this principle on a CW signal.
As you can see on the left-hand side, no amplitudes exist above or below the box; the density of the signal
is 100%. On the right hand side, there are signals below the box, therefore the density is less than 100%.
uld make the box so narrow that it contained only points within a single column of pixels, the
sity, calculated by adding the column density sums then dividing by the number of columns. For a 100%
RSA6100B Series & RSA5100A Series Printable Help61
General Signal ViewingDPX Primer
Figure 24. Density of signals defined within an area. Left: Correct measurement of a CW signal. All columns in the
box inclu
expected. Some columns in the box contain no hits, so they contribute zeros to the calculation of average density.
The density measurement box' vertical size and location are always set in dB and dBm, no matter what
units you have selected for measurements. (Amplitude control panel > Units tab) The box is not draggable
when the selected units are linear (such as Amps, Volts, Watts…), though you can still adjust its size and
location using the Frequency and Amplitude controls in both the DPX Settings > Density and Trigger >
Event ta bs. Since the vertical scale is non-linear, a box of constant amplitude changes visual height as it
chang
de the signal. Right: Incorrect measurement area. The measurement is accurate, but probably not what you
es vertical position, a disconcerting effect if you are trying to drag it.
Figure 25. DPX Density control panel is used to define the area of interest for DPX density measurements.
A readout will appear somewhere in the graph. If the box is off-screen, the readout will be accompanied by
an arrow pointing towards the invisible box. Grab this readout with your mouse or finger and drag the
density readout to the area you want to measure.
To adjust the box size, a mouse is the easiest way to drag the sides and corners of the rectangle. For precise
settings, use the knob, arrow keys, or keyboard to adjust frequency and amplitude values for the rectangle.
These controls are located in the right half of the Density tab in the control panel.
Persistence
Previous sections of this topic have assumed that persistence was not applied to the DPX bitmap. Without
persistence, hit counts in the grid are cleared after each frame update. Now we will describe how
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General Signal ViewingDPX Primer
persistence modifies this behavior, starting with infinite persistence because it is simpler than variable
persistence.
Hit counts are not cleared between frames if infinite persistence is enabled. When the instrument is set
up for continuous acquisitions, hits keep collecting until you stop acquisitions or click the Clear button
above the DPX display. Software keeps track of the total number of waveforms computed during the
entire collection period. Density equals the total number of hits to a cell divided by the total number of
waveforms.
Variable persistence is trickier. A single-occurrence signal shown in the bitmap does not disappear
suddenly upon the next frame update, nor does it linger forever. It fades gradually away. The user sets
a time constant for the Dot Persistence control which determines how long it takes for signals to fade.
Fading is accomplished by reducing the hit count in every cell, after each frame update, by a factor based
on the persistence time constant. The longer the time constant, the less the hit counts are reduced.
Figure 26. Example of fast transient discovery with and without variable persistence turned on. In the display on the
left, with variable persistence of 10 seconds, the occasional sub-second transient that spikes up above the normal
signals is held in the display rather than disappearing as soon as the signal goes away. The display on the right, with
persistence turned off, requires watching the display continually to see the brief signal.
Not only are single-occurrence signals allowed to remain in the display for awhile by variable persistence,
additional hits keep piling on. The result is that cell values are no longer pure hit counts; they include
counts due to new hits from waveforms plus proportionally reduced counts from prior frames. As part
of translating hit counts into density values, a new software algorithm uses a finite-series equation to
discriminate between the effects of persist ence and the arrival of new hits. The inflationary effects of
persistence on cell counts are removed, so density readings represent the true ratio of actual hits to possible
hits over the persistence interval.
The density computation for variable persistence is a very good estimate of true signal density, with errors
of less than 0.01%. For exact density measurements, use either no persistence or infinite persistence.
Another subtlety of persistence is its smoothing effect on the density measurement of intermittent signals.
Consider a pulse that is on for 10 ms and off for 90 ms of each 100-ms cycle. We'll make the simplifying
assumption that the pulse ON time always falls entirely within a single DPX frame update (50 ms). If
persistence is not applied, the density measurement is computed on each individual frame. The results
will be 20% for each frame containing the ON time and 0% for the other frames. If infinite persistence
RSA6100B Series & RSA5100A Series Printable Help63
General Signal ViewingDPX Primer
is enabled, however, the density measurement will settle to 10% after the second frame, and remain at
this value for as long as the pulsing continues. With persistence, the density is effectively computed
over many fram
es.
Persistence Effects on Density
Persistence does not alter colors in a density-based bitmap. Its effect is to extend the amount of time over
which densities are calculated, leaving signal events visible for the persistence duration.
Before the introduction of density measurements and extra-long hit counters, persistence caused colors
to “bloom”, becoming more and more intense over time as the hit counts increased. Longer persistence
intervals caused increased blooming, turning crisp signals into fat red stripes. When hit counts are
converted to density values (RSA6100B Series and RSA5000A Series with Option 200), the display is not
subject to this effect. As long as the input signals maintain reasonably stable repetition rates and duty ratios,
their den
If you are accustomed to the original hit-count-based persistence displays, it may seem counterintuitive
that rep
persistence. A quick review of the density algorithm explains why: the hit count is divided by the total
number of waveforms over the persistence interval. For example, if a signal occupies a pixel 50% of the
time over a period of 15 minutes, the density reading will be 50% throughout the entire 15 minutes,
though the underlying hit count is steadily increasing.
sity values will also remain stable despite ever-increasing hit counts in the underlying grid cells.
eating signals in a density-based bitmap will not get brighter and redder over time with infinite
is Resolution
Z-Ax
Another factor that can cause color bloom is overflow of the hit counters. If a pixel could only count up to
0 hits, its density and color values would clip at 100% after just 1000 hits, even if waveform points
100
continue to arrive in the same pixel location. With waveform points being written to the bitmap at rates
approaching 300k/sec, counts add up really fast for highly-repetitive signals. Deeper counters permit
higher hit counts, so overflow happens much later, as shown in Table 3.
Table 4: Comparison of DPX z-axis resolution and its effect on saturation.
RSA6100B SeriesRSA5100A Series with Option 200
Hit Count36-bit custom float (equivalent to
33-bit integer)
Maximum Hit Count
Minimum Time until Overflow (for
pixels with 100% density)
xxx
8.1 hours8.1 hours
36-bit custom float (equivalent to
33-bit integer)
Clipping due to overflow of the counters in one or more cells will not occur until hours have passed, or
even days.
Onemorebenefit to having deeper hit counters is better visual resolution of density. RSAs with the
highest-performance DPX hardware installed use floating-point numbers to count hits, allowing us to count
billions of waveforms while retaining one-hit resolution, providing better than 99 dB of dynamic range
for density measurements. Density measurements in μ%, n%, and even f% ranges are quite possible for
extremely rare signals captured with infinite persistence.
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With straight-line mapping between density and color (Curve setting of 1), resolution is fixed by the
number of colors in the palette. For non-linear mappings (Curve settings higher or lower than 1), most
of the colors a
discriminate finer differences between density values in that range.
re concentrated at either the low or high end of the density scale, so you can visually
Persistence Adjustments
Dot Persistence can be enabled for the “Bitmap” trace using the Settings control panel. The Persistence
can be displayed as Infinite or Variable. For Variable Persistence, you can select the time constant for
fading in seconds as shown in Figure 27.
Figure 27. The trace settings control panel allows user control of persistence p
Figure 28 demonstrates the observed behavior of variable persistence when a CW signal, represented in
the first frame, is turned off. Even if the event was instantaneous and was confined within a single frame,
you will observe the color changing to indicate lower and lower density values, until the signal finally
disappears entirely.
Figure 28. With variable persistence, a brief CW signal captured by DPX remains in the display for an adjustable
periodoftimebeforefadingaway.
arameters.
DPX Density Trigger
The standard DPX display shows you a clear picture of transients and other hard-to-find signals. The
version of DPX in the RSA6100B series and RSA5100A series with option 200 goes well beyond helping
you discover these difficult to find signals by actually triggering on their appearance to capture them into
acquisition memory for in-depth analysis. If you can see it in the DPX bitmap, you can trigger on it.
Other trigger methods can detect signals that e
amplitude-vs-frequency m ask, but they can't find a signal a t a particular frequency if another signal of
higher amplitude is sometimes present at that same frequency. The Runt trigger addresses some of these
signal-under-signal cases, but not all. As shown in Figure 29, the DPX Density trigger can discriminate
signals within a precise amplitude-frequency range without the operator having to know any characteristics
of the target signal besides where it might show up in the D PX Spectrum graph.
RSA6100B Series & RSA5100A Series Printable Help65
xceed an amplitude threshold, or even a sophisticated
General Signal ViewingDPX Primer
Figure 29. Example of Density Trigger. Left: A free-run DPX display showing pulses with varying frequency.
Occasionally, a short pulse in the middle appears for a split instant, but it is hard to capture it with just a Run/Stop
button. Right: The triggered DPX displays shows the low-amplitude pulse that was not apparent in the untriggered
display. The analyzer was set to trigger whenever the average density in the user-drawn box measured 50% or higher.
The DPX Density trigger uses the same screen-based measurement box as the DPX Density measurement.
While the
box. When the target signal finally appears, the density value increases. The trigger system m onitors the
density measurement and activates a trigger whenever the density value exceeds the adjustable density
threshold. The only thinking you have to do is to set this threshold to a level somewhere between the
normal density readings and the density due to the trouble-making signal. However, the instrument
software can compute the threshold value automatically.
target signal is absent, the density measurement characterizes the “normal” signals within the
Trigger On This™
The Tr
right-clicking on a spot within the DPX display, or pressing and holding your finger on the RSA6100B
Series touchscr een display for about a second, a menu selection will appear. Selecting Trig ger On This
causes a DPX Density box to appear and automatically adjusts the threshold. The DPX display will now
only update whenever the automatic threshold is exc eeded. Subsequently, if needed for your signal,
open the Trigger control panel to adjust the density threshold or the size of the measurement box until
th
igger On This™ function allows you to point and click to set up the DPX Density trigger. By
e event is reliably captured.
Automatic Threshold Adjustment by Trigger On This™
The trigger density threshold automatically set by Trigger On This is 80% of the measured value. If the
signal wa s present at the moment you selected Trigger On This, the threshold will be 20% less than the
signal density, so the next time the signal is present long enough (or present enough times) to exceed
the threshold density, it will cause a trigger. If the signal happened to be missing when you selected
Trigger On This, the threshold value will be even lower. If you clicked in a part of the display with no
signal activity at all, the threshold will be set to zero. Any signal that shows up here will fire the trigger,
as shown in Figure 32.
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Figure 30. The analyzer triggered when the density in the DPX measurement box exceeded the threshold set by
Trigger On This. You can see in the Spectrogram and Frequency-vs-Time displays that the signal event which caused
the trigger was a quick frequency hop. The Time Overview shows that the signal amplitude never changed, so a
power level trigger would not have worked.
DPX Density Trigger Timing
The time resolution for DPX density measurements is the frame length, around 50 ms. A basic
implementation of the DPX Density trigger concept is also frame-based, so a trigger event that occurs
anywhere within a frame will not be recognized until the end of the frame. Therefore, the worst case
trigger uncertainty is 50 ms.
DPX Density trigger doesn't always have to wait until the end of a frame before firing. For the
common configuration of triggering when the measured density is higher than the threshold, the density
measurement in the trigger can be computed many times within each frame and it can fire the trigger
soon as the threshold is exceeded.
as
Consider the case where the threshold is zero. As soon as a single waveform causes a hit within the
easurement box, we know that the density is greater than zero. It takes a little longer to test for a 5 or
m
10% density, and even more time for thresholds at or near 100%.
The DPX Density trigger can also be set to fire when the measured density is below the threshold value.
This is useful when you suspect that your signal is missing some of the time. For a signal that is supposed
to be CW, you can set the trigger controls to acquire when the density measurement of the signal peak
drops below 100%. When using the “lower than” form of the DPX Density trigger, the time resolution is
RSA6100B Series & RSA5100A Series Printable Help67
General Signal ViewingDPX Display Overview
one frame because of the following logic: We can't be sure the actual density is less than, say, 15% until at
least 85% of the full test time has elapsed. In order to keep things simple and fast in the trigger module, the
RSA just waits
until the end of each 50 ms frame to do the “lower than” comparisons.
Persistence and DPX Density Trigger
The smoothing effect of persistence on density measurements can help in d etermining a good threshold
value. With persistence turned off, an infrequent signal's density reading jumps between higher and lower
values as it turns on and off, and it can be hard to read these flashing numbers. By turning persistence
on, you instruct the instrument to average the density over a longer time period. This density result is
somewhere between the ON and OFF density values - the very definition of a good trigger threshold.
Unlike the DPX Density measurement, the DPX Density trigger is not affected in any way by persistence.
Density calculations in the trigger system are made with hit count data received from each individual DPX
frame, before any persistence is a pplied. Even when the density measurement reading in the display
is averaged over many frames due to persistence, the trigger is computing density for each frame and
comparing these quick snapshots against the threshold setting.
DPX Display Overview
The DPX display enables you to see how traces change over time and thus displays signal events that
cannot be seen on a swept spectrum analyzer. A DPX Spectrum indicates how traces change in two ways.
First, it uses color shading to show how consistent the shape of a trace is. Second, it uses persistence to
hold signals on the screen so you can see them longer.
DPX Display
The DPX display works by using a two-dimensional array to represent
trace writes to a point on the display, a counter in the array is incremented. A color is assigned to each point
in the display based on the value of its counter. Thus, as acquisitions occur over time, a colored waveform,
the Bitmap, develops on the display that shows how frequently each display point has been written to.
An important feature of the DPX display is dot persistence. Dot persistence sets how long a point on the
display will be visible. You can set the Dot Persistence to be Variable or Infinite. In variable persistence
mode, you specify a decay period that limits how long a point will be displayed. In infinite persistence
mode, once a point in the display has been written to, it will remain visible indefinitely.
The DPX display can plot the trace in the following views:
Spectrum – This view p lots power on the vertical axis versus frequency on the horizontal axis. This
display is similar to a standard Spectrum display.
points on the display. Each time a
Zero Span (RSA6100B Series and RSA5000A Series with Option 200) – This view plots power on
the vertical axis versus time on the horizontal axis. This display shows how the power level at the
center frequency changes with time.
68RSA6100B Series & RSA5100A Series Printable Help
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Frequency (RSA6100B Series and RSA5000A Series with Option 200) - This view plots frequency
on the vertical axis versus time on the horizontal axis. This displays how frequency changes over
time, where th
also available in the Frequency plot.
e center frequency is displayed at the center of the vertical axis. Tx BER testing is
Phase (RSA61
vertical axis versus time on the horizontal axis. This displays how phase changes over time, where the
zero degree phase position is displayed at the center of the vertical axis.
DPXogram (RSA6100B Series and RSA5000A Series with Option 200) - This view is a spectrogram
version (time plotted along the vertical axis versus frequency on the horizontal axis) of the DPX
Spectrum trace. DPX spectrogram creates the spectrogram in real time, and does not require an
acquisition to be transferred into memory and analyzed. Because of this real time processing, there are
no gaps in the spectral lines, even for monitoring periods that can last for several days.
The DPXogram has the following limitations:
DPXogram cannot sweep a range greater than the maximum real-time bandwidth. When
the instrument is sweeping, the DPXogram display shows the Disabled - data is from sweptacquisition message.
No overlap, however, DPXogram can display multiple Spectrums/line.
The DPXogram monitors in real time and can be used as a monitor while triggers are occurring. It
cannot be set to display only triggered lines.
Split (RSA6100B Series and RSA5100A Series with Option 200) This view consists of two DPX
views. A DPXogram view appears on the top half of the display and a DPX Spectrum view appears on
the bottom half of the display.
To display a DPX view:
00B Series and RSA5000A Series with Option 200) - This view plots phase on the
1. Select Freq and use the front panel knob or number keys to set the measurement frequency.
2. Select the Displays button or Setup > Displays. This displays the Select Displays dialog box.
3. From the Folders box, select General Signal Viewing.
elect DPX from the Available displays box.
4.S
5. Click the Add button. This will add the DPX icon to the Selected Displays box (and remove it from
the Available displays box).
6. Click the OK button. This displays the DPX Spectrum view.
7. Select the desired view from the drop-down list on the left side of the graph.
RSA6100B Series & RSA5100A Series Printable Help69
General Signal ViewingDPX Display
DPX Zero Span view
DPX Split View
70RSA6100B Series & RSA5100A Series Printable Help
General Signal ViewingDPX Display
Elements of the DPX Display
ItemDisplay elementDescription
1Vert Position
2
3RBW
4DPX view
5
6
7
8
9Function
dB/divSets the vertical scale value. The maximum value is 20.00 dB/division.
AutoscaleAdjusts the Vertical and Horizontal scaling to display the entire trace on screen.
Pos/CFSpectrum: Center Frequency - Adjusts the analyzer center frequency. For Zero
Span/Scale, Sweep/ScaleSpectrum display: Span - Adjusts frequency range of the measurement. Scale - If
ClearErases the bitmap and traces in the graph and restarts multi-trace functions
Sets the top of graph value. This is only a visual control for panning the graph.
The Reference Level is adjusted in the Toolbar and the Ampl control panel. By
default, Vert Position = Ref Level.
Sets the resolution bandwidth. Note that when the RBW is set to Auto, its value is
italicized.
Selects the DPX view. Choices are Spectrum, Zero Span, Frequency, Phase,
DPXogram, and Split.
Span, Frequency, or Phase the Position is in seconds.
Horizontal scale has been manually adjusted in Settings > Scale, then this control
adjusts the visual graph scaling without affecting the Span. Zero Span, Frequency,
Phase displays: Sweep - adjusts the trace duration in s econds. Scale - adjusts the
visual graph scaling without affecting the Sweep time.
(Avg, Hold).
Readout of the Detection and Function selections for the selected trace.
RSA6100B Series & RSA5100A Series Printable Help71
General Signal ViewingDPX Display
ItemDisplay elementDescription
10
ShowControls whether the selected Trace is visible or not. When trace is Off, the box is
not checked.
11Trace
Selects a trac
e. Touching here pops up a context menu listing the available
traces, whether they are enabled or not. If user selects a trace that is not currently
enabled, it will be made enabled.
xxx
Additional Elements of the DPXogram Split Display
ItemDisplay elementDescription
1
Spectrums/lineAppears only when the display is stopped. Readout of the number of spectrum
lines represented by each line of the DPXOgram display. This value changes
when the Time/div or Time resolution settings are changed.
2
Color scaleLegend at the right side of the DPX Spectrum display. This element illustrates the
relationship between the colors in the DPXogram plot and the amplitude axis of the
DPX Spectrum plot.. This scale changes with Color (DPXogram) palette selection
and Max and Miin settings on the Ampl Scale tab.
3DPXogram trace
The selected line in the DPXogram graph can be shown in the DPX Spectrum
graph of the Split view. The most recent DPXogram line, usually at the bottom
of the graph, is selected by default. If any markers are on, the selected marker
determines the selected line.
xxx
Time Reso lution of DPXogram Display
Due to the large amount of data produced by the DPX hardware during acquisitions, a compressed version
of the plot is shown while running. This plot is limited to 500 lines, with each line having 267 points.
However, a much longer record, with higher frequency resolution is being collected. As soon as the
instrument is stopped, this underlying data is shown, replacing the temporary version. There are 50 lines
in each vertical division of the 2-D DPXogram plot, so the time resolution of the graph is Time/div
72RSA6100B Series & RSA5100A Series Printable Help
General Signal ViewingDPX Display
divided by 50. However, you can set the instrument to collect multiple spectra per line, allowing you to
zoom in later on this high-time-resolution data.
When the DPXogram display is stopped, the analyzer can display the full resolution of the captured data.
The Time Resolution readout applies only when the DPXogram is running.
Effects of Changing Time Resolution. The Time Resolution control affects acquisition parameters for the
DPX hardware. This means that if you change the Time Resolution value while the instrument is stopped,
the new value applies to the NEXT acquisition, and might not represent the results currently shown in
the display.
Time resolution can be changed either directly, by manually adjusting the Time Resolution control, or
automatically, by changing the Time/div control. Auto is the default, yielding one spectrum per line in the
display. When the Time Resolution is decreased below its auto value, multiple spectra are collected to
create each line in the DPXogram graph. Once you stop the instrument, you can decrease the Time/div
value or use Zoom to see increased time resolution.
If the time resolution is set to a very small number while the Time/div is set to a large value, you might
notice that there is a limit to the number of spectra that can be collected. This limit depends on the number
of trace points selected. For 801-point spectra, 60,000 underlying spectra can be collected. The number of
2401-point spectra collected is 20,000, and for 4001-point spectra the number is 12,000. When the limit is
reached, the oldest spectra are discarded as newer spectra are captured.
Touchscreen Actions on Markers in the Graph Area
ActionDescription
Mouse click within 1/2 div. of
amarker
Touch marker to select and
then use knob, or arrow keys
Touch and drag a marker
xxx
Selects the marker and updates the marker display to show the selected marker's values.
Adjust the setting associated with the Marker.
Changes marker position to the "drop point". You can use Tools > Options > Prefs to
change whether markers jump from one peak to the next while dragging or move smoothly
along the trace.
Available Traces for Disp lay – Standard Instrument
Five traces can be shown in the DPX display– one bitmap and four line traces. The default traces are
Bitmap and +Peak detection. The other three traces are –Peak detection, average detection, and math.
RSA6100B Series & RSA5100A Series Printable Help73
General Signal ViewingDPX Display
TraceDescription
Bitmap
+Peak detecte
–Peak detected
Average detected
Math Trace
xxx
d
Displays the density of acquired data. The number of data points acquired at each pixel
(representin
by color.
Line trace. Displays the maximum values acquired in each update. Normal and Hold functions
are available for this trace.
Line trace. Displays the minimum values acquired in each update. Normal and Hold functions
are availab
Line trace.
functions are available for this trace.
Line trace. Displays the difference between two traces. The two traces used are set in the
Traces tab of the Settings panel.
g a particular amplitude level at a specific frequency at a point in time) is indicated
le for this trace.
Displays the average of all the values acquired in each update. Normal and Hold
Determining Which Trace Types Are Displayed
You can see the status of all the traces by selecting the Trace drop-down list. Traces that are not displayed
are preceded by "Enable". In the following figure, you can tell that the Bitmap and -Peak Trace traces are
displayed but the +Peak, Average, and Math Traces are not displayed.
Selecting Enable -Peak Trace from the Trace list displays the -Peak detected values trace.
an see whether a trace is enabled by looking at its Show check box. The "selected trace" is selected
You c
in the Trace list. The Show check box is checked when the selected trace is e nabled. To the right of the
show box are readouts for detection of the selected trace (+Pk, Avg (VRMS), ) and its function (Hold,
Normal,). You can enable/disable the selected trace by checking or unchecking Show.
Selecting Traces for Display – Standard Instrument
To select a trace for display:
74RSA6100B Series & RSA5100A Series Printable Help
General Signal ViewingDPX Display
1. Use the Settings control panel:
Select Setup > Settings or click the Settings button.
Select the Trac es tab.
Select the trace from the drop-down menu.
Select the S
2. Select a trace from the Trace drop-down list.
Specify
You control how the +Peak, –Peak and Average (Avg (VRMS)) traces are displayed from the Traces tab of
the Set
from single updates or results collected over multiple updates.
To cha
1. Select Setup > Settings or click the Settings button.
2. Select the Trac es tab.
ing How +Peak, –Peak, and Average Traces Are Displayed
tings control panel. From the Traces tab, you can also specify whether these traces display results
nge how the traces are displayed:
how check box.
3. Select the trace type from the drop-down list.
4. If you select +Peak Trace or -Peak Trace, use the Function drop-down list to select either Normal or
Hold.
a. Select Normal to set the trace to display the maximum/minimum values acquired in each
individual update.
b. Select Hold to set the trace to display the maximum/minimum values acquired over time. The
trace values are updated only if they exceed the existing values.
5. If you select Avg (VRMS) or Avg (of logs), use the Function drop-down list to select either Normal,
Average (V RMS ),orAvg (of logs).
a. Select N ormal to set the trace to display the average values acquired in each update.
b. Select Average (VRMS) or Avg (of logs) to set the trace to display an average of the average
values. Use the Count box to enter the number of times the trace is averaged.
RSA6100B Series & RSA5100A Series Printable Help75
General Signal ViewingDPX Display
Available Traces for Display (RSA6100B Series and RSA5000A Series with Option 200)
Five traces can be shown in the DPX Spectrum, Zero Span, Frequency, and Phase displays– one bitmap
and four line traces. The default traces are Bitmap and Trace 1. The other three traces are 2, 3, and Math.
Line traces 1, 2, and 3 have user-selectable Detection and Function settings. The final line trace is Math,
allowing you
For the DPXogram display, only one trace is available — the DPXogram trace.
For the Split display, which consists of a DPXogram display on the top half and a DPX Spectrum display
on the bottom half, you can display the Bitmap trace, Trace 1, Trace 2, Trace 3, Math trace, and Ogram
Line (the s
to subtract one line trace from another.
elected line from the DPXogram display) on the bottom half of the display.
Selecting Traces for Display (RSA6100B Series and RSA5000A Series with Option 200)
This is done almost the same as with the standard instrument, except that the choices available for Trace
are different. Instead of +Pk, –Pk, and Avg traces, you select Trace 1, 2, and 3 and independently set the
Detection method for each of these traces to +Pk, -Pk, Avg (VRMS), or Avg (of logs).
Reference. Changing the DPX Spectrum Display Settings
(see page 276)
Tx BER Testing in the DPX Frequency View
The Tr
modulated on a carrier. The modulation type supported is a 2-level FSK signal (2FSK) with a symbol rate
of 16 KHz. Tx BER is available only in the DPX Frequency plot.
The Ce nte r Frequency must be set to the carrier frequency. The RBW or Meas urement BW must be set
high enough to pass the full frequency deviation of the modulated signal. The vertical scaling on the
display does not affect the measurement. The measurement is also unaffected by trigger settings.
The 16k symbol/second rate has a tolerance of +-10ppm. The data patterns supported are PRBS-9,
PRBS-11, PRBS-15, and User.
The User pattern is a user-defined fixed pattern of arbitrary length up to 30 seconds in duration. The
synchronization pattern (of length "n") can be specified to be up to 32 bits, and is the first "n" bits of the
user's pattern. The test duration with User pattern can be one time through or repeating. If PRBS lengths
other than the three listed above are needed, the User pattern can be used in repeating mode to get any
PRBS length up to PRBS-18.
When a test is started, the incoming data is sampled to seed the PRBS receiver or find the starting
pattern for User pattern. If errors are occurring in the signal, it is possible to get a spurious match at
test start time, resulting in an invalid measurement. In this case, for a PRBS pattern the error rate will
be 50%, and for User pattern the rate will be pattern-dependent. If this happens, the test can be restarted
with the Clear results function. The symbol count, error count, and error rate (BER) are displayed on
the screen. For a User pattern, the measurement starts after the synchronization pattern has been seen,
so the synchronization pattern symbols are not included as part of the symbol count, although they are
included in the pattern length.
ansmit Bit Error Rate Testing (Tx BER) function measures the bit error rate in a data stream
To measure Tx BER, see Tx BER Tab
76RSA6100B Series & RSA5100A Series Printable Help
(see page 90).
General Signal ViewingDPX Settings
DPX Settings
Menu Bar: Setup > Settings
Front Panel / Application Toolbar: Settings
The measurement settings for the DPX display are shown in the following table.
Settings tab
Freq & Span (see page 118)Sets frequency and span parameters for the DPX display. This tab appears for the
Params (see page 78)Sets sweep time and scroll settings. This tab appears only for the DPX Zero Span,
Freq & BW (
BW (see page 124)Sets Resolution Bandwidth.
Traces (Bitmap) Tab (see
page 79)
Traces Tab (see page 82)Allows you to select the number and types of traces to display and their functions.
Traces (Math) Tab (see
page 123)
Horiz
page 85)
Bitmap Scale Tab (see
page 86)
Amplitude Scale Tab (s ee
e
pag
me Freq Scale Tab
Ti
page 88)
Prefs (see page 126)Specifies whether certain display elements are visible.
Density (see page 89)Specifies location and size for the DPX Density measurement box. (Spectrum display
Tx BER Tab (see page 90)Specifies BER testing parameters. (Frequency plot only).
Audio Demod (see page 93)Enables and sets parameters for audio demodulation function.
xxx
see page
&VertScaleTab
87)
79)
(see
(see
Description
Spectrum and DPXogram displays.
DPX Freque
TheFreq&
Span, DPX Frequency, and DPX Phase views.
Allows you to configure the Bitmap Trace.
Allows you to configure the Math Trace.
Sets t
Sets the DPX Bitmap display parameters.
The Amplitude Scale tab allows you to change the vertical scale and offset, enable the
Waterfall display, and set the color scheme used for the DPXogram trace.
3-D
e Time and Freq Scale tab allows you to change the v ertical and horizontal scale
Th
settings, number of points in the trace, and Time resolution.
only; RSA6100B Series and RSA5100A Series with Option 200)
ncy and DPX Phase displays.
BW tab specifies frequency and bandwidth parameters for the DPX Zero
he vertical and horizontal scale parameters for all the DPX views.
RSA6100B Series & RSA5100A Series Printable Help77
General Signal ViewingParams Tab – DPX Zero Span, DPX Frequency and DPX Phase Views
Params Tab – DPX Zero Span, DPX Frequency and D PX Phase Views
The Params tab sets the sweep time for the DPX Zero Span, Frequency and Phase views. Use the Params
tab to set the scroll mode settings for the DPX Zero Span, Frequency and Phase views. In Scroll mode,
points of the
an acquisition is completed.
Params tab settings Zero Span, Frequency and Phase views
trace are plotted as they occur, as opposed to normal mode where the trace is plotted after
Setting
Sweep timeSets the time period for the measurement. By default, the Horizontal Scale is equal to
Trace motion for Sweep
≥ 1sec
Normal
Roll
None
xxx
Description
Sweep ti
sweep time extends beyond the left and/or right edges of the graph. Range: 100 ns –
2000 s. Default: 1 ms.
Specifies how the trace is displayed when the sweep time is equal to or greater than
1seco
Selec
mode, a caret (^) moves below the graph to indicate the latest position.
Select Roll to scroll the trace as points are added at the right side of the graph. When
Roll is selected, the trace moves to the left as points are added to the trace at the right
side
Sel
me and the sweep covers 10 divisions. When the graph is zoomed in, the
nd.
t Normal to scroll the position at which data points are added to the trace. In this
of the graph.
ect None to display the trace without motion.
78RSA6100B Series & RSA5100A Series Printable Help
General Signal ViewingFreq & BW Tab – DPX Zero Span, DPX Frequency and DPX Phase Views
Freq & BW Tab – DPX Zero Span, DPX Frequency and DPX Phase Views
The Fre q & BW tab specifies frequency parameters for some of the DPX display views.
Freq & BW tab settings for the bitmap trace (Standard and option 200)
Setting
Center FrequencySets the frequency at the center of the measurement bandwidth.
Step SizeSets the increment size when changing the Frequency using the knob or mouse wheel.
Auto
Measurement BW, no filterSpecifies the measurement bandwidth.
RBW (Time-domain BW) filterRBW (Time-domain BW) is a filter used to process the input signal before the system
Actual BW
xxx
Traces Tab – Bitmap
The Traces Tab allows you to set the display characteristics of displayed traces in the DPX display. The
Traces tab for the DPX display has two versions: one for the DPX Bitmap trace (described in this topic)
and one for line traces
Description
Arrow keys have an increment 10 times this setting.
When Auto is enabled, the step size is adjusted automatically based on Spectrum's
span setting.
analyzes the signal. The filter value determines the acquisition bandwidth that the view
requires. Range: 1 HZ to 60 MHz.
Shows the actual bandwidth being used for the display.
(see page 82).
Traces tab – Bitmap trace (RSA6100B and RSA5000A with Option 200)
RSA6100B Series & RSA5100A Series Printable Help79
General Signal ViewingTraces Tab – Bitmap
Traces tab – D
PXogram trace (RSA6100B and RSA5000A with Option 200)
Traces tab settings for the bitmap trace (RSA6100B and RSA5000A with Option 200)
Setting
Trace
ShowSpecifies
Detectio
only)
Intensity (standard instrument
only)
Dot Per
VariableThe Variable dot persistence setting controls how long a point in the display is visible
InfiniteThe Infinite dot persistence setting prevents a point in the display from fading (not
FreezeHalts updates to the selected trace.
Save Trace AsSaves the selected trace to a file for later recall and analysis.
Show Recalled TraceDisplays a saved trace instead of a live trace (not available for the DPXogram trace).
xxx
n (DPXogram trace
sistence
Description
Select Bit
Sets the D
methods are +Peak, -Peak, and Avg (VRMS).
Use Intensity to control the visibility of events. An increased intensity level allows a
single, short event to be seen. This also makes such an event subject to the persistence
contro
events. Range is 1-100%. Resolution: 1.
Allows a dot to remain visible if it is not updated with new data. Choices for this setting
are Variable and Infinite. (Not available for the DPXogram trace.)
before fading (not available for the DPXogram trace). This setting has no units
assoc
Range: 1–1000. Resolution 0.1.
RSA6100B Series and RSA5000A Series with Option 200 Range: 50 ms–100 s.
ava
map or DPXogram to set the parameters of the DPX Bitmap or DPXogram trace.
whether or not the selected trace is displayed.
etection method
ls. This allows you to see the effect of the Persistence controls on infrequent
iated with it.
ilable for the DPXogram trace).
(see page 120) used for the trace. Available detection
Dot Persistence
Dot Persistence is the characteristic of the DPX display that determines how long a pixel in the display
remains visible.
To set the Persistence:
1. Select Setup > Settings.
2. Select the Traces tab.
3. Select Dot Persistence.
80RSA6100B Series & RSA5100A Series Printable Help
General Signal ViewingTraces Tab – Bitmap
4. Select either Infinite or Varia b le.
5. If you select Variable, enter a value in the text box. The Variable persistence value can be s et from
0.05 to 100 seconds (RSA6100B and RSA5000A with Option 200) and 1 to 1000 in the RSA5000A
instruments without option 200.
Saving Traces
Tosaveatra
1. Select the Save Trace As button. This displays the Save As dialog box.
2. Navigate to the location where you want to save the file.
ce for later analysis:
3. Type a name for the saved trace and click Save.
Show Recalled Trace
You can recall a previously saved trace for comparison to a live trace. First, specify a trace for recall and
second, enable Show Recalled Trace.
To select a trace for recall:
1. Select the ... button to display the Open dialog box.
RSA6100B Series & RSA5100A Series Printable Help81
General Signal ViewingTraces Tab
2. In the Open dialog, navigate to the location of the saved trace.
3. Select the desired trace file.
4. Select OK to complete your selection.
5. Select the S
6. Verify that the trace's Show check box is selected (either on this tab or next to the drop-down list
located at t
Traces Tab
The Traces Tab allows you to set the display characteristics of displayed traces in the DPX display. The
Traces tab for the DPX display has two versions. One for non-Bitmap traces (described in this topic)
and one for the DPX Bitmap trace
Traces tab (RSA6100B and RSA5000A with Option 200)
how recalled trace check box.
he top-left corner of the graph).
(see page 79).
Setting
Trace drop-down list
ShowSpecifies whether or not the trace shown in the Trace setting is displayed.
FreezeHalts updates to the selected trace.
Detection (RSA6100B and
RSA5000A with Option 200)
Function
Save Trace AsSaves the selected trace to a file for later recall and analysis.
Show Recalled TraceDisplays a saved trace instead of a live trace.
CountEnables user adjustable number of averages. This setting is only present when Function
xxx
Description
Selects which trace to configure. The available traces are Bitmap, Trace 1, Trace 2,
Trace 3, and Math (RSA6100B series and RSA5100A series with Option 200). For
RSA5000A series instruments without Option 200, the available traces are Bitmap,
+Peak detected, -Peak detected, Average, and Math.
Sets the Detection method used for the trace. Available detection methods are +Peak,
-Peak, and Avg (VRMS). Not all detection methods are available in all displays.
Selects the trace processing method. Available settings are: Normal, Average, and Hold.
= Average.
82RSA6100B Series & RSA5100A Series Printable Help
General Signal ViewingTraces Tab
Detection
Trace Detection occurs when the trace is being decimated by the measurement. For example, if the
maximum number of trace points is 100,000, and the selected analysis region is 200,000 samples, the
measurement must decimate the 200,000 resulting trace points by 2 to prevent exceeding the 100,000 trace
point limit.
(detect) the appropriate value to use.
Since only one value can be selected for each trace point, an algorithm must be used to select
The availab
le detection methods are:
+Peak – Each point on the trace is the result of detecting the positive peak value present in the set of
IQ samples
available to that trace point.
-Peak – Each point on the trace is the result of detecting the negative peak value present in the set of
IQ sample
Avg (VR MS) [Average V
value fo
s available to that trace point.
] – Each point on the trace is the result of determining the RMS Voltage
RMS
r all of the IQ samples available to the trace point. When displayed in either linear (Volts,
Watts) or Log (dB, dBm), the correct RMS value resu lts. When the averaging function is applied to a
trace, the averaging is performed on the linear (Voltage) values, resulting in the correct average
for RMS values.
NOTE. The Detection setting does not affect the trace until the spectrum length is longer than the Auto
setting.
DPX Trace Process ing
Peak, -Peak, and Average traces can be processed to display in different ways. The Function setting
The +
controls trace processing.
d - Displays the value in the trace record for each display point. Each new trace display point is
Hol
compared to the previous maximum value and the greater value is retained for display and subsequent
comparisons. Available for traces using +Peak or -Peak detection.
Normal - Displays the trace record for each display point without additional processing. Available
for all detection selections.
Average - Default setting for the Average. Multiple traces are averaged together to generate the
displayed trace. There is one vertical value for each underlying frequency data point. Once the
specified number of traces have been acquired and averaged to generate the displayed trace, each new
trace takes the place of the oldest trace in the calculation. The Count setting specifies how many
traces are averaged. Available for traces using Average detection.
Trace averaging uses the exponential method. If Count = 10, the newest trace's contribution to the
averaged trace is 10%. When Count is not checked, the algorithm assumes the maximum number of
traces contributing to the average is
.
Saving Traces
To save a trace for late r analysis:
RSA6100B Series & RSA5100A Series Printable Help83
General Signal ViewingTraces Tab
1. Select the Save Trace As button. This displays the Save As dialog box.
2. Type a name for the saved trace and click Save.
Recalling Traces
You can recall a previously saved trace for comparison to a live trace. First, specify a trace for recall and
second, enable Show Recalled Trace.
To select a trace for recall:
1. Click the ... button to display the Open dialog box.
2. Navigate to the desired file and click Open.
3. Check the Show Recalled Trace check box.
4. Verify that the trace's Show check box is selected (either on this tab or next to the drop-down list
located at the top-left corner of the graph).
84RSA6100B Series & RSA5100A Series Printable Help
General Signal ViewingHoriz & Vert Scale Tab
Horiz & Vert Scale Tab
The Horiz & Vert Scale tab allows you to change the vertical scale settings used for the Bitmap trace.
Changing the scale settings changes how the trace appears on the display but does not change control
settings suc
h as Measurement Frequency.
Setting
Vertical
Description
Controls the vertical position and scale of the trace display.
ScaleChanges the vertical scale.
OffsetAdjusts the Reference Level away from the top of the trace display.
Reset ScaleSets Scale to its default value and Offset to zero. Disabled when Units (Setup > Analysis
> Units) is set to Watts or Volts.
Autoscale
Resets the scale of the vertical axis to contain the complete trace. Disabled when Units
(Setup > Analysis > Units) is set to Watts or Volts.
Horizontal
Controls the horizontal position and scale of the trace display.
ScaleChanges the horizontal scale.
Position
Autoscale
x
xx
Adjusts the horizontal position of the signal. This does not change the center frequency.
Resets the scale of the horizontal ax is to contain the complete trace.
RSA6100B Series & RSA5100A Series Printable Help85
General Signal ViewingBitmap Scale Tab
Bitmap Scale Tab
The Bitmap Scale tab allows you to set the color sc heme used for the Bitmap trace. Changing the DPX
bitmap Color, Max and Min scale settings changes how the trace appears o n the display but does not
change contr
ol settings such as Measurement Frequency.
Setting
DPX Bitma
CurveAdjus
Auto
xxx
p (Signal Density)
ColorAllows y
Max
Min
Color
Description
Controls
Sets the
densities greater than this value.
Range: 1p% - 100%; Default: 100%.
Sets the hit density represented by the bottom of the color range. Range: 0 - 80%;
Defau
= 1), or it can be set to concentrate the resolution on the lower level of the range (Curve >
1) or the mapping can be set to show the best resolution on the upper range of density
or hi
Adju
the appearance and scale of the DPX Bitmap trace.
ou to select the color palette used for the DPX Bitmap trace.
hit density represented by the top of the color scale. "Clipping" occurs for
lt: 0.
ts how colors are mapped to the signal density. The mapping can be linear (Curve
t count (Curve < 1).
sts the Max and Min settings to display the broadest range of colors.
86RSA6100B Series & RSA5100A Series Printable Help
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