Keysight N9030A, X Series, N9020A, N9000A, N9038A Measurement Manual

Keysight X-Series Signal Analyzers

This manual provides documentation for the following Analyzers:

PXA Signal Analyzer N9030A MXA Signal Analyzer N9020A
EXA Signal Analyzer N9010A CXA Signal Analyzer N9000A
MXE EMI Receiver N9038A

Notice: This document contains references to Agilent.
Please note that Agilent’s Test and Measurement business
has become Keysight Technologies. For more information,
go to www.keysight.com.

N9063A &
W9063A
Analog Demod
Measurement
Application
Measurement
Guide

Notices

© Keysight Technologies, Inc.
2008-2014

No part of this manual may be
reproduced in any form or by any
means (including electronic storage
and retrieval or translation into a
foreign language) without prior
agreement and written consent from
Keysight Technologies, Inc. as
governed by United States and
international copyright laws.

Trademark Acknowledgements

Manual Part Number

N9063-90006

Print Date

August 2014

Supersedes: February 2012

Printed in USA

Keysight Technologies Inc.
1400 Fountaingrove Parkway
Santa Rosa, CA 95403

Warranty

THE MATERIAL CONTAINED IN THIS
DOCUMENT IS PROVIDED “AS IS,”
AND IS SUBJECT TO BEING
CHANGED, WITHOUT NOTICE, IN
FUTURE EDITIONS. FURTHER, TO THE
MAXIMUM EXTENT PERMITTED BY
APPLICABLE LAW, KEYSIGHT
DISCLAIMS ALL WARRANTIES,
EITHER EXPRESS OR IMPLIED WITH
REGARD TO THIS MANUAL AND ANY
INFORMATION CONTAINED HEREIN,
INCLUDING BUT NOT LIMITED TO THE
IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE.
KEYSIGHT SHALL NOT BE LIABLE FOR
ERRORS OR FOR INCIDENTAL OR
CONSEQUENTIAL DAMAGES IN
CONNECTION WITH THE
FURNISHING, USE, OR
PERFORMANCE OF THIS DOCUMENT
OR ANY INFORMATION CONTAINED
HEREIN. SHOULD KEYSIGHT AND THE
USER HAVE A SEPARATE WRITTEN
AGREEMENT WITH WARRANTY
TERMS COVERING THE MATERIAL IN
THIS DOCUMENT THAT CONFLICT
WITH THESE TERMS, THE
WARRANTY TERMS IN THE SEPARATE
AGREEMENT WILL CONTROL.

Technology Licenses

The hardware and/or software
described in this document are
furnished under a license and may be
used or copied only in accordance
with the terms of such license.

If software is for use in the
performance of a U.S. Government
prime contract or subcontract,
Software is delivered and licensed as
“Commercial computer software” as
defined in DFAR 252.227-7014 (June

1995), or as a “commercial item” as
defined in FAR 2.101(a) or as
“Restricted computer software” as
defined in FAR 52.227-19 (June 1987)
or any equivalent agency regulation or
contract clause. Use, duplication or
disclosure of Software is subject to
Keysight Technologies’ standard
commercial license terms, and
non-DOD Departments and Agencies
of the U.S. Government will receive no
greater than Restricted Rights as
defined in FAR 52.227-19(c)(1-2)
(June 1987). U.S. Government users
will receive no greater than Limited
Rights as defined in FAR 52.227-14
(June 1987) or DFAR 252.227-7015
(b)(2) (November 1995), as applicable
in any technical data.

Safety Notices

CAUTION

A CAUTION notice denotes a hazard. It
calls attention to an operating
procedure, practice, or the like that, if
not correctly performed or adhered to,
could result in damage to the product
or loss of important data. Do not
proceed beyond a CAUTION notice
until the indicated conditions are fully
understood and met.

WARNING

A WARNING notice denotes a hazard.
It calls attention to an operating
procedure, practice, or the like that, if
not correctly performed or adhered to,
could result in personal injury or
death. Do not proceed beyond a
WARNING notice until the indicated
conditions are fully understood and
met.

Restricted Rights Legend

Where to Find the Latest Information

Documentation is updated periodically. For the latest information about these products, including instrument software
upgrades, application information, and product information, browse to one of the following URLs, according to the name of
your product:

http://www.keysight.com/find/pxa

http://www.keysight.com/find/mxa

http://www.keysight.com/find/exa

http://www.keysight.com/find/cxa

http://www.keysight.com/find/mxe

To receive the latest updates by email, subscribe to Keysight Email Updates at the following URL:

http://www.keysight.com/find/emailupdates

Information on preventing analyzer damage can be found at:

http://www.keysight.com/find/tips

Is your product software up-to-date?

Periodically, Keysight releases software updates to fix known defects and incorporate product enhancements. To search for
software updates for your product, go to the Keysight Technical Support website at:

http://www.keysight.com/find/techsupport

3

4

Table of Contents

1 Demodulating AM, FM, ΦM, FM Stereo/RDS Signals

Setting Up and Making a Measurement 8

Making the Initial Signal Connection 8

Using Analyzer Mode and Measurement Presets 8

The 3 Steps to Set Up and Make Measurements 9

Demodulating an AM Signal 11

Demodulating an FM Signal 12

Demodulating an FM Stereo/RDS Signal 13

Measuring L Only FM Stereo/RDS Signals 13

Measuring L=R FM Stereo/RDS Signals 19

Contents

2Concepts

AM Concepts 26

FM Concepts 28

FM Stereo/RDS Concepts 30

FM Stereo 30

RDS/RBDS 30

Demodulating an AM Signal Using the Analyzer as a Fixed Tuned Receiver
(Time-Domain) 32

Demodulating an FM Signal Using the Analyzer as a Fixed Tuned Receiver
(Time-Domain) 33

Demodulating an FM Stereo/RDS Signal Using the Analyzer as a Fixed Tuned
Receiver (Time-Domain) 34

Modulation Distortion Measurement Concepts 35

Purpose 35

Measurement Technique 35

Modulation SINAD Measurement Concepts 36

Purpose 36

Measurement Technique 36

5

Contents

6

Demodulating AM, FM, ΦM, FM Stereo/RDS Signals

1 Demodulating AM, FM, ΦM, FM Stereo/RDS

Signals

The Analog Demod measurement application provides the capability of
demodulating AM (amplitude modulated), FM (frequency modulated), ΦM (phase
modulated), and FM Stereo/RDS (Radio Data System) signals. These measurements
provide functionalities that can generally be categorized as follows:

• Demodulating a modulated carrier and playing the modulating signal over a

speaker (sometimes referred to as tune and listen)

• Displaying demodulated signals in both time and frequency domains

• Displaying modulation metrics

• Displaying the RDS information in FM Stereo/RDS signals

The following topics can be found in this section:

“Setting Up and Making a Measurement” on page 8

“Demodulating an AM Signal” on page 11

“Demodulating an FM Signal” on page 12

“Demodulating an FM Stereo/RDS Signal” on page 13

7

Demodulating AM, FM, ΦM, FM Stereo/RDS Signals

X-Series Signal Analyzer

EXT REF IN

Optional

RF OUTPUT

Attenuator

RF INPUT

AM, FM, M,

or FM Stereo/RDS Transmitter

Φ

EXT REF OUT

Setting Up and Making a Measurement

Setting Up and Making a Measurement

Making the Initial Signal Connection

Set the AM, FM, ΦM, or FM Stereo/RDS transmitter under test to transmit the RF
power. Connect the transmitting signal to the signal analyzer as below.

CAUTION Before connecting a signal to the analyzer, make sure the analyz er ca n sa fely ac c ep t

the signal level provided. The signal level limits are marked next to the RF Input
connector on the front panel.

1. Connect the output AM, FM, ΦM, or FM Stereo/RDS transmitter to the RF input
port of the signal analyzer using appropriate cables, attenuators, and adapters.

2. (Optional) If there is a frequency reference port on the transmitter, connect it to
the EXT REF IN port on the signal analyzer for frequency synchronization.

Figure 1-1 AM, FM,

After making the connection, see the Input/Output key menu for details on
selecting input ports and the AMPTD Y Scale menu for details on setting internal
attenuation to prevent overloading the analyzer.

Using Analyzer Mode and Measurement Presets

T o set your current measurement mode to a known factory default state, press Mode
Preset. This initializes the analyzer by returning the mode setup and all of the

measurement setups in the mode to the factory default parameters.

Φ

M, or FM Stereo/RDS Measurement System

To preset the parameters that are specific to an active, selected measurement, press
Meas Setup, Meas Preset. This returns all the measurement setup parameters to the
factory defaults, but only for the currently selected measurement.

8

Demodulating AM, FM, ΦM, FM Stereo/RDS Signals

The 3 Steps to Set Up and Make Measurements

All measurements can be set up using the following three steps. The sequence starts
at the Mode level, is followed by the Measurement level, then finally, the result
displays may be adjusted.

Table 1-1 The 3 Steps to Set Up and Make a Measurement

Step Action Notes

Setting Up and Making a Measurement

1 Select and Set Up the

Mode

2 Select and Set Up the

Measurement

3 Select and Set Up a

View of the Results

a. Press Mode.
b. Press Analog Demod.
c. Press Mode Preset.
d. Press Mode Setup.

a. Press Meas.

b. Select the specific measurement

to be performed.

c. Press Meas Setup.

Press View/Display. Select a
display format for the current
measurement data.

All licensed, installed modes
available are shown under the Mode
key.

Using Mode Setup, make any
required adjustments to the mode
settings. These settings will apply to
all measurements in the mode.

The measurement begins as soon as
any required trigger conditions are
met. The resulting data is shown on
the display or is available for export.

Use Meas Setup to make any
required adjustment to the selected
measurement settings. The settings
only apply to this measurement.

Depending on the mode and
measurement selected, other
graphical and tabular data
presentations may be available.
X-Scale and Y-Scale adjustments
may also be made now.

NOTE A setting may be reset at any time, and will be in effect on the next measurement

cycle or view.

Table 1-2 Main Keys and Functions for Making Measurements

Step Primary Key Setup Keys Related Keys

1 Select and set up a mode. Mode Mode Setup,

2 Select and set up a

measurement.

System

FREQ Channel

Meas Meas Setup Sweep/Control,

Restart, Single, Cont

9

Demodulating AM, FM, ΦM, FM Stereo/RDS Signals
Setting Up and Making a Measurement

Table 1-2 Main Keys and Functions for Making Measurements

Step Primary Key Setup Keys Related Keys

3 Select and set up a view of the

results.

View/Display SPAN X Scale ,

AMPTD Y Scale

Peak Search,
Quick Save, Save,
Recall, File, Print

NOTE If you encounter a problem, or get an error message, see the guide “Instrument

Messages”, which is provided on the Documentation CD ROM, and in the

instrument here:
C:\Program Files\Keysight\SignalAnalysis\Infrastructure\Help\bookfiles.

10

Demodulating AM, FM, ΦM, FM Stereo/RDS Signals

Demodulating an AM Signal

This section demonstrates how to demodulate and listen to an AM signal. You can
tune to an AM signal and view the results of the detector output displayed in the
quad-view window or in single-window format.

Alternatively, the demodulated signal is also available as an audio output (to the
speaker or headphone jack) and as video output (on the rear panel).

The signal under test is a 680 kHz signal with AM depth of 50% and AM rate of 1
kHz. Note that if you are using a broadcast AM signal in the United States, for
example, the AM channels are broadcasting between 550 kHz and 1650 kHz.

Step Action Notes

1 Select Analog Demod mode. Press Mode, Analog Demod.
2 Preset the mode. Press Mode Preset.
3 Select AM measurement. Press Meas, AM.

Demodulating an AM Signal

4 Set the center frequency of

the AM signal.

5 Adjust the sweep time and

view the measurement
results as in the figure
below.

Press FREQ Channel, Center
Freq, 680, kHz.

Press Sweep/Control, Demod
Wfm Sweep Time, 2, ms.

6 Listen to the demodulated

AM signal.

Press Meas Setup, Demod to
Speaker.

11

You may need to adjust the volume
as necessary.