Spectrum Analyzer Mode Measurement Guide

212 Pages·2012·8.39 MB·English

by  Agilent Technologies

Agilent X-Series
Signal Analyzer
This manual provides documentation for

the following X-Series Instruments:

PXA Signal Analyzer N9030A
MXA Signal Analyzer N9020A
EXA Signal Analyzer N9010A
CXA Signal Analyzer N9000A
MXE EMI Receiver N9038A
Spectrum Analyzer Mode
Measurement Guide
Notices
© Agilent Technologies, Inc. 2008-2012 Manual Part Number licensed as “Commercial computer soft-
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Warranty
This Agilent technologies instrument product is warranted against defects in material and workmanship for
a period of one year from the date of shipment. During the warranty period, Agilent Technologies will, at
its option, either repair or replace products that prove to be defective.
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Where to Find the Latest Information
Documentation is updated periodically. For the latest information about this analyzer, including firmware
upgrades, application information, and product information, see the following URLs:
http://www.agilent.com/find/pxa
http://www.agilent.com/find/mxa
http://www.agilent.com/find/exa
http://www.agilent.com/find/cxa
To receive the latest updates by email, subscribe to Agilent Email Updates:
http://www.agilent.com/find/emailupdates
Information on preventing analyzer damage can be found at:
http://www.agilent.com/find/tips
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Contents
1 Getting Started with the Spectrum Analyzer Measurement Application
Making a Basic Measurement 12
Using the front panel 12
Presetting the signal analyzer 13
Viewing a signal 14
Recommended Test Equipment 17
Accessories Available 18
50 ohm load 18
50 ohm/75 ohm minimum loss pad 18
75 ohm matching transformer 18
AC probe 18
AC probe (low frequency) 19
Broadband preamplifiers and power amplifiers 19
GPIB cable 19
USB/GPIB cable 19
RF and Transient Limiters 19
Power splitters 20
Static safety accessories 20
2 Measuring Multiple Signals
Comparing Signals on the Same Screen Using Marker Delta 22
Comparing Signals not on the Same Screen Using Marker Delta 25
Resolving Signals of Equal Amplitude 28
Resolving Small Signals Hidden by Large Signals 33
Decreasing the Frequency Span Around the Signal 37
Easily Measure Varying Levels of Modulated Power Compared to a Reference 39
−
3 Measuring a Low Level Signal
Reducing Input Attenuation 44
Decreasing the Resolution Bandwidth 47
Using the Average Detector and Increased Sweep Time 50
Trace Averaging 52
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4 Improving Frequency Resolution and Accuracy
Using a Frequency Counter to Improve Frequency Resolution and Accuracy 56
5 Tracking Drifting Signals
Measuring a Source Frequency Drift 58
Tracking a Signal 61
6 Making Distortion Measurements
Identifying Analyzer Generated Distortion 64
Third-Order Intermodulation Distortion 67
7 Measuring Noise
Measuring Signal-to-Noise 72
Measuring Noise Using the Noise Marker 74
Measuring Noise-Like Signals Using Band/Interval Density Markers 78
Measuring Noise-Like Signals Using the Channel Power Measurement 81
Measuring Signal-to-Noise of a Modulated Carrier 83
Improving Phase Noise Measurements by Subtracting Signal Analyzer Noise 88
8 Making Time-Gated Measurements
Generating a Pulsed-RF FM Signal 94
Signal source setup 94
Analyzer setup 95
Digitizing oscilloscope setup 97
Connecting the Instruments to Make Time-Gated Measurements 99
Gated LO Measurement 100
Gated Video Measurement 104
Gated FFT Measurement 108
9 Measuring Digital Communications Signals
Channel Power Measurements 112
Occupied Bandwidth Measurements 114
Troubleshooting hints 115
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Making Adjacent Channel Power (ACP) Measurements 116
Making Statistical Power Measurements (CCDF) 121
Making Burst Power Measurements 126
Spurious Emissions Measurements 132
Troubleshooting hints 134
Spectrum Emission Mask Measurements 135
Troubleshooting hints 136
10 Demodulating AM Signals
Measuring the Modulation Rate of an AM Signal 140
Measuring the Modulation Index of an AM Signal 144
11 IQ Analyzer Measurement
Capturing Wideband Signals for Further Analysis 148
Complex Spectrum Measurement 149
IQ Waveform (Time Domain) Measurement 151
12 Using Option BBA Baseband I/Q Inputs
Baseband I/Q measurements available for X-Series Signal Analyzers 156
Baseband I/Q measurement overview 157
13 Option EXM External Mixing
Using Option EXM with the Agilent 11970 Series Mixers. 160
Amplitude calibration 161
Loading conversion loss data for the PXA Signal Analyzer 161
Signal ID 165
Image shift 165
Using the M1970 Series Mixers with X-Series Signal Analyzers (Option EXM) 167
Operating precautions 167
Equipment set up 168
Operation 169
Amplitude calibration 170
LO adjustment 170
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Viewing the external mixer setup screen 171
14 Concepts
Resolving Closely Spaced Signals 174
Resolving signals of equal amplitude 174
Resolving small signals hidden by large signals 174
Trigger Concepts 176
Selecting a trigger 176
Time Gating Concepts 179
Introduction: Using Time Gating on a Simplified Digital Radio Signal 179
How time gating works 181
Measuring a complex/unknown signal 187
“Quick Rules” for making time-gated measurements 192
Using the Edge Mode or Level Mode for triggering 195
Noise measurements using Time Gating 196
AM and FM Demodulation Concepts 197
Demodulating an AM signal using the analyzer as a fixed tuned receiver
(Time-Domain) 197
Demodulating an FM signal using the analyzer as a fixed tuned receiver
(Time-Domain) 197
IQ Analysis Concepts 198
Purpose 198
Complex Spectrum measurement 198
IQ Waveform Measurement 199
Spurious Emissions Measurement Concepts 200
Purpose 200
Measurement method 200
Spectrum Emission Mask Measurement Concepts 201
Purpose 201
Measurement method 201
Occupied Bandwidth Measurement Concepts 202
Purpose 202
Measurement method 202
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Baseband I/Q Inputs (Option BBA) Measurement Concepts 203
What are Baseband I/Q inputs? 203
What are Baseband I/Q signals? 203
Why make measurements at baseband? 204
Selecting input probes for baseband measurements 205
Baseband I/Q measurement views 206
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