Keysight Technologies N5244/5B User manual

Service Guide
)
N5244/5B 2-Port and 4-Port
PNA-X Microwave Network
Analyzers - Service Guide
N5244/5B Series -
(900 Hz/10 MHz - 43.5 GHz)
(900 Hz/10 MHz - 50 GHz)
This is the Service Guide for the N5244/5BSeries Microwave Network Analyzers.

Notices
© Keysight Technologies, Inc.
2010-2023
No part of this manual may be
reproduced in any form or by any
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and retrieval or translation into a
foreign language) without prior
agreement and written consent
from Keysight Technologies, Inc. as
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international copyright laws.
Trademark Acknowledgments
Manual Part Number
N5245-90026
Edition
Edition 1, February 2023
Printed in USA/Malaysia
Published by:
Keysight Technologies
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 TOTHIS MANUAL AND
ANY INFORMATION CONTAINED
HEREIN, INCLUDING BUT NOT
LIMITED TOTHE IMPLIED
WARRANTIES OF
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FOR ERRORS OR FORINCIDENTAL
OR CONSEQUENTIAL DAMAGES IN
CONNECTION WITH THE
FURNISHING, USE, OR
PERFORMANCE OF THIS
DOCUMENT OR ANY INFORMATION
CONTAINED HEREIN. SHOULD
KEYSIGHT AND THE USERHAVE 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.
U.S. Government Rights
The Software is “commercial
computer software,” as defined
by Federal Acquisition Regulation
(“FAR”) 2.101. Pursuant to FAR
12.212 and 27.405-3 and
Department of Defense FAR
Supplement (“DFARS”) 227.7202,
the U.S. government acquires
commercial computer software
under the same terms by which
the software is customarily
provided to the public.
Accordingly, Keysight provides
the Software to U.S. government
customers under its standard
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embodied in its End User License
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which can be found at
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among other things, that
Keysight: (1) Furnish technical
information related to
commercial computer software
or commercial computer
software documentation that is
not customarily provided to the
public; or (2) Relinquish to, or
otherwise provide, the
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extent that those terms, rights, or
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set forth specifically in writing
elsewhere in the EULA. Keysight
shall be under no obligation to
update, revise or otherwise
modify the Software. With
respect to any technical data as
defined by FAR 2.101, pursuant
to FAR 12.211 and 27.404.2 and
DFARS 227.7102, the U.S.
government acquires no greater
than Limited Rights as defined in
FAR 27.401 or DFAR 227.7103-5
(c), as applicable in any technical
data.
Safety Notices
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.
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.

3

4

Contents
Keysight N5244B/45B Service Guide 5
1. Safety and Regulatory Information
Information in This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Chapter One at-a-Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Safety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
General Safety Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Safety Earth Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Before Applying Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Electrostatic Discharge Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
Regulatory Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Instrument Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Lithium Battery Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
2. General Product Information
Information in This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Chapter Two at-a-Glance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Physical Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Electrical Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Analyzer Options, Accessories, and Upgrades Available. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Pulse I/O Adapter-N1966A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Required Service Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Keysight Support, Services, and Assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Service and Support Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Contacting Keysight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Shipping Your Analyzer to Keysight for Service or Repair. . . . . . . . . . . . . . . . . . . . . . . . 2-8
3. Tests and Adjustments
Information in This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Conventions Used for Hardkeys, Softkeys, and Menu Items. . . . . . . . . . . . . . . . . . . . . . 3-1
Chapter Three at-a-Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Before You Begin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Verify the Operating Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Protect Against Electrostatic Discharge (ESD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
Allow the Analyzer to Warm Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
Review the Principles of Connector Care. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
About System Verification and Performance Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
System Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
Instrument Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
System Verification Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8

6 Keysight N5244B/45B Service Guide
Contents
Performance Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
Certificate of Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
ANSI/NCSL Z540.3–2006 and ISO/IEC Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
Non-Standards Compliant Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
Preliminary Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
The Operator’s Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
The Test Port Cable Checks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
System Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
What the System Verification Verifies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
Measurement Uncertainty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-22
Measurement Traceability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-23
Performing System Verification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24
Performance Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-32
Source Power Accuracy Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-32
Source Maximum Power Output Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33
Source Power Linearity Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34
Frequency Accuracy Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-35
Trace Noise Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-36
Receiver Compression Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37
Noise Floor Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-38
Calibration Coefficients Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-39
Dynamic Accuracy Test – Version 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-40
Dynamic Accuracy Test – Version 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-41
Receiver Noise Figure Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-43
Noise State Calibration Coefficients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-44
Noise Jitter Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-44
Noise Receiver Linearity Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-45
Noise Receiver Compression Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-46
Dynamic Accuracy at Low Frequency (Available With Low Frequency Extension (LFE)
Installed Option 205/220/420/425) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-48
DC Continuity Test the LFE Board and Test Ports (Available With Low Frequency Extension
(LFE) Installed Option 205/220/405/420/425). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-50
Adjustments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-51
Touchscreen Adjustment and Verification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-51
10 MHz Frequency Reference Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-52
Synthesizer Bandwidth Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-53
Source Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-53
IF Gain Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-54
Receiver Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-54
Receiver Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-55
EE Default Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-57

Contents
Keysight N5244B/45B Service Guide 7
IF Response Adjustment (Available Only with Option S93093/4A/B and or
S93900/1/2/4/5/7A/B Installed) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-57
Noise Figure Adjustment (Available with Option 029 with S93029A/B Installed) . . . . 3-58
LFE Receiver Adjustment (Available With Low Frequency Extension (LFE) Installed Option
205/220/420/425) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-61
4. Troubleshooting
Information in This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Chapter Four at-a-Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Conventions Used for Hardkeys, Softkeys, and Menu Items. . . . . . . . . . . . . . . . . . . . . . 4-3
Operating the Analyzer With Covers Removed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Protect Against Electrostatic Discharge (ESD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
Assembly Replacement Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
Getting Started with Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7
Check the Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7
Troubleshooting Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8
Power Up Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9
Power Supply Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10
Troubleshooting LCD Display Problems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15
Front Panel Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
Front Panel Keypad and RPG Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17
A3 Display Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20
Checking the A2 USB Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21
A1 Front Panel Interface Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22
Rear Panel Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24
Checking the USB Ports. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24
Checking the CONTROLLER Port. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24
LAN Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-25
Measurement System Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-31
Before you begin—consider: Where do you see a problem? . . . . . . . . . . . . . . . . . . . . . 4-31
Verifying the A, B, C, D, and R Traces (Standard S-Parameter Mode) . . . . . . . . . . . . . 4-33
Where to Begin Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-34
Checking the Source Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-37
Checking the Signal Separation Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-48
Checking the Receiver Group. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-52
Instrument Simplified Block Diagrams – LFE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-56
2-Port N5290A System Block Diagram (201 and 205) . . . . . . . . . . . . . . . . . . . . . . . . . 4-56
2-Port N5290A System Block Diagram (202 and 205) . . . . . . . . . . . . . . . . . . . . . . . . . 4-57
4-Port N5290A System Block Diagram (401) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-58
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-61
Instrument Block Diagrams – 2-Port (Sheet 1), Non-LFE and Non-DDS (Version 6

8 Keysight N5244B/45B Service Guide
Contents
Synthesizers) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-62
Microwave PNA-X, N5244/5B – 2-Port, Non-LFE and Non-DDS (Version 6 Synthesizers) .
4-62
Instrument Block Diagrams – 2-Port (Sheet 2), Non-LFE and DDS (Version 7 Synthesizer
Assemblies) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-64
Microwave PNA-X, N5244/5B – 2-Port, Non-LFE and DDS (Version 7 Synthesizer
Assemblies) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-64
Instrument Block Diagrams – 4-Port (Sheet 3), Non-LFE and Non-DDS (Version 6
Synthesizers) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-66
Microwave PNA-X, N5244/5B – 4-Port, Non-LFE and Non-DDS (Version 6 Synthesizers) .
4-66
Instrument Block Diagrams – 4-Port (Sheet 4), LFE and Non-DDS (Version 6 Synthesizers) . .
4-68
Microwave PNA-X, N5244/5B – 4-Port, LFE and Non-DDS (Version 6 Synthesizers) . 4-68
Instrument Block Diagrams – 4-Port (Sheet 5), Non-LFE and DDS (Version 7 Synthesizer
Assemblies) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-70
Microwave PNA-X, N5244/5B – 4-Port, Non-LFE and DDS (Version 7 Synthesizer
Assemblies) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-70
Instrument Block Diagrams – 4-Port (Sheet 6), LFE and DDS (Version 7 Synthesizer
Assemblies) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-72
Microwave PNA-X, N5244/5B – 4-Port, LFE and DDS (Version 7 Synthesizer Assemblies).
4-72
5. Theory of Operations
Information in This Chapter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1
Chapter Five at-a-Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Network Analyzer System Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
Functional Groups of the Network Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
Synthesized Source Group Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10
Basic Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11
A4, A15, and A17 13.5 GHz Synthesizer Boards (S/N Prefixes <6021 Only) . . . . . . . . . 5-23
A15 Version 7 Digital to Digital Synthesizer (DDS) Assembly (S/N Prefixes ≥6021 Only). . .
5-23
A5 and A10 26.5 GHz Source Boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25
A7, A8, A12, and A13 50 GHz Doubler Boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25
A25 Multiplier/Amplifier 26.5 Board (HMA26.5). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26
A14 Frequency Reference Board (S/N prefixes <6021 Only) . . . . . . . . . . . . . . . . . . . . . 5-26
A23 Test Set Motherboard. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27
A70 4-Port and A75 2-Port Low Frequency Extension (LFE) Board. . . . . . . . . . . . . . . . 5-30
Signal Separation Group Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-44
Configurable Test Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-44
A29–A32 Reference Couplers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-45

Contents
Keysight N5244B/45B Service Guide 9
A33–A36 Test Port Couplers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-45
A38–A41 60-dB Source Step Attenuators and A42–A45 Bias Tees (Optional) . . . . . . 5-49
A38–A41 60-dB Source Step Attenuators and A71–74 Bias Tee Combiners (Optional) . . .
5-49
A50–A53 Mechanical Switches and A54 Combiner (Optional) . . . . . . . . . . . . . . . . . . . 5-49
Receiver Group Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-51
A46–A49 35-dB Receiver Step Attenuators (Optional) . . . . . . . . . . . . . . . . . . . . . . . . 5-51
A37 Reference Mixer Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-51
A27 and A28 Mixer Bricks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-51
A24 IF Multiplexer Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-52
A16 SPAM Board (Analog Description) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-53
Digital Processing and Digital Control Group Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . 5-57
Front Panel Subgroup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-59
Data Acquisition and Processing Subgroup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-60
Power Supply Group Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-62
Noise Measurement Group Operation (Option S93029A) . . . . . . . . . . . . . . . . . . . . . . . . . . 5-62
A56 Test Port 1 Option 029 Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-63
A64 Test Port 1 Option 029 Tuner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-63
A57 Test Port 2 Option 029 Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-63
A59 Noise Receiver (Downconverter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-63
A9 Noise Receiver Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-63
6. Replaceable Parts
Information in This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
Chapter Six at-a-Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3
Assembly Replacement Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
Rebuilt-Exchange Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
Replaceable Parts Listings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Front Panel Assembly, Front Side, All Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13
Front Panel Assembly, Back Side, All Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-15
Top Assemblies and Cables, All Options, Serial Number Prefixes <6021 . . . . . . . . . . . 6-19
Top Assemblies and Cables, All Options, Serial Number Prefixes ≥6021 . . . . . . . . . . . 6-27
2-Port Configurations, Serial Number Prefixes <6021 . . . . . . . . . . . . . . . . . . . . . . . . . 6-34
2-Port Configurations, Serial Number Prefix ≥6021 . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-81
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-128
4-Port Configuration, Serial Number Prefix <6021 . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-129
4-Port Configurations, Serial Number Prefix ≥6021 . . . . . . . . . . . . . . . . . . . . . . . . . . 6-208
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-288
Rear Panel Assembly, All Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-289
Fan Assemblies, All Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-291

10 Keysight N5244B/45B Service Guide
Contents
Top Hardware and Miscellaneous Parts, All Options . . . . . . . . . . . . . . . . . . . . . . . . . .6-293
Bottom Hardware and Miscellaneous Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-295
Internal Hardware and Miscellaneous Parts, All Options . . . . . . . . . . . . . . . . . . . . . . .6-299
External Hardware and Miscellaneous Parts, All Options . . . . . . . . . . . . . . . . . . . . . . 6-301
Miscellaneous Part Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-303
7. Repair and Replacement Procedures
Information in This Chapter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-2
Chapter Seven at-a-Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
Personal Safety Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
Electrostatic Discharge (ESD) Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4
Removal and Replacement Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5
Removing the Covers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8
Removing and Replacing the Front Panel Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10
Removing and Replacing the A1–A3 and Other Front Panel Subassemblies . . . . . . . . . . . 7-12
Removing and Replacing the A4–A17 Boards
(For analyzers with serial numbers prefixed MY/SG/US5150 and below) . . . . . . . . . . . . . . 7-20
Removing and Replacing the A4–A17 Boards
(For analyzers with serial numbers prefixed MY/SG/US5201 and above) . . . . . . . . . . . . . . 7-24
Removing and Replacing the A18 System Motherboard . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-27
Removing and Replacing the A19 Midplane Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-30
Removing and Replacing the A20 Power Supply Assembly. . . . . . . . . . . . . . . . . . . . . . . . . 7-32
Removing and Replacing the A21 CPU Board Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-34
Removing and Replacing the A22 GPIB Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-36
Removing and Replacing the A23 Test Set Motherboard. . . . . . . . . . . . . . . . . . . . . . . . . . . 7-38
Removing and Replacing the A24 IF Multiplexer Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-41
Removing and Replacing the A25 HMA26.5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-43
Verify the Model/Version of HMA26.5 Installed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-45
Removing and Replacing the A26 Splitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-46
Removing and Replacing the A27 and A28 Mixer Bricks . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-48
Removing and Replacing the A29–A32 Reference Couplers and Reference Coupler Mounting
Brackets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-51
Removing and Replacing the A33–A36 Test Port Couplers . . . . . . . . . . . . . . . . . . . . . . . . . 7-53
Removing and Replacing the A37 Reference Mixer Switch . . . . . . . . . . . . . . . . . . . . . . . . . 7-55
Removing and Replacing the A38–A41 Source Attenuators and the A46–A49 Receiver
Attenuators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-57
Removing and Replacing the A42–A45 Bias Tees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-59
Removing and Replacing the A50–A53 Bypass Switches and the A54 Combiner . . . . . . . 7-61
Removing and Replacing the A55 Solid State Drive (SSD) . . . . . . . . . . . . . . . . . . . . . . . . . 7-64

Contents
Keysight N5244B/45B Service Guide 11
Removing and Replacing the A56 Port 1 Noise Bypass Switch (Option 029). . . . . . . . . . . 7-66
Removing and Replacing the A57 Port 2 Noise Bypass Switch and A59 Noise Receiver
(Downconverter) – (Option 029). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-69
Removing and Replacing the A64 Tuner (Option 029) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-71
Removing and Replacing the A70 or A75 Low Frequency Extension (LFE) Board . . . . . . . 7-74
Removing and Replacing the A71–A74 Bias Tee Combiners . . . . . . . . . . . . . . . . . . . . . . . 7-80
Removing and Replacing the Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-85
Removing and Replacing the Front Panel LED Boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-87
Removing and Replacing the Fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-89
Removing and Replacing the Lithium Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-91
Post-Repair Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-93
Resetting the Mechanical Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-104
EEPROM Backup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-105
8. General Purpose Maintenance Procedures
Information in This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
Chapter Eight at-a-Glance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
Conventions Used for Hardkeys, Softkeys, and Menu Items. . . . . . . . . . . . . . . . . . . . . . 8-1
Error Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2
Using Error Terms as a Diagnostic Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2
Performing Measurement Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3
Using Flowgraphs to Identify Error Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3
Accessing Error Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6
Error Term Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-8
Keysight License Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-11
Accessing the Keysight License Manager Software . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-11
Software Entitlement Certificate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-11
Enabling or Removing Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-12
Repairing and Recovering Option Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-13
Installing or Changing a Serial Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-13
Firmware Upgrades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-14
How to Check the Current Firmware Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-14
Downloading from the Internet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-14
Operating System Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-15
Recovering from Solid State Drive Problems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-15
Correction Constants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-16
Storing Correction Constants. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-16
A:.EEPROM Address Assignments and Location (N5224/5A&B PNA and N5244/5A&B PNA-X
Instruments)

12 Keysight N5244B/45B Service Guide
Contents

1-1
Keysight Microwave Network Analyzers
2-Port and 4-Port PNA-X
Service Guide
1 Safety and Regulatory Information
Information in This Chapter
This chapter provides safety information that will help protect you and your
network analyzer. It also contains information that is required by various
government regulatory agencies.
Chapter One at-a-Glance
Section Title Summary of Content Start Page
Safety Symbols Descriptions of CAUTION and WARNING symbols used
throughout this manual.
page 1-2
General Safety Considerations A list of safety points to consider when servicing your
network analyzer.
page 1-3
Electrostatic Discharge Protection A discussion of electrostatic discharge (ESD) and
related recommendations and requirements for ESD
protection.
page 1-7
Regulatory Information Definitions of instrument markings.
Instructions for disposing of the analyzer’s lithium
battery.
page 1-9

1-2 Keysight N5244B/45B Service Guide
Safety and Regulatory Information
Safety Symbols
1-
Safety Symbols
The following safety symbols are used throughout this manual. Familiarize
yourself with each of the symbols and its meaning before operating this
instrument.
Caution denotes a hazard. It calls attention to a procedure that, if not
correctly performed or adhered to, could result in damage to or
destruction of the instrument. Do not proceed beyond a caution note until
the indicated conditions are fully understood and met.
Warning denotes a hazard. It calls attention to a procedure which, if
not correctly performed or adhered to, could result in injury or loss
of life. Do not proceed beyond a warning note until the indicated
conditions are fully understood and met.

Keysight N5244B/45B Service Guide 1-3
Safety and Regulatory Information
General Safety Considerations
General Safety Considerations
Safety Earth Ground
Before Applying Power
This is a Safety Class I product (provided with a protective earthing
ground incorporated in the power cord). The mains plug shall only
be inserted in a socket outlet provided with a protective earth
contact. Any interruption of the protective conductor, inside or
outside of the instrument, will make the instrument dangerous.
Intentional interruption is prohibited.
Use Keysight supplied power cord or one with same or better
electrical rating.
Always use the three-prong AC power cord supplied with this product.
Failure to ensure adequate grounding by not using this cord may cause
product damage.
If this product is not used as specified, the protection provided by
the equipment could be impaired. This product must be used in a
normal condition (in which all means for protection are intact) only.
If an instrument handle is damaged, you should replace it
immediately. Damaged handles can break while you are moving or
lifting the instrument and cause personal injury or damage to the
instrument.
Supply voltages which oscillate between the two normal input
ranges of the autoranging line voltage input will damage the power
supply. In rare cases, this damage has become a user safety
concern. If unstable power levels are expected, the analyzer input
power must be buffered by a line conditioner.
This instrument has autoranging line voltage input. Be sure the supply
voltage is within the specified range.
This product is designed for use in Installation Category II and Pollution
Degree 2 per IEC 61010-1:2001 and 664 respectively.

1-4 Keysight N5244B/45B Service Guide
Safety and Regulatory Information
General Safety Considerations
1-
Do not operate the analyzer with the outer cover removed for more than
30 minutes, as this could cause the analyzer to overheat which could
result in costly damage.
Ventilation Requirements: When installing the product in a cabinet, the
convection into and out of the product must not be restricted. The ambient
temperature (outside the cabinet) must be less than the maximum
operating temperature of the instrument by 4 °C for every 100 watts
dissipated in the cabinet. If the total power dissipated in the cabinet is
greater than 800 watts, then forced convection must be used.
The measuring terminals on this instrument are designed to be used with
external signals described in Measurement Category I, but NOT with
external signals described in Categories II, III, and IV. The input of this
instrument cannot be connected to the mains.

Keysight N5244B/45B Service Guide 1-5
Safety and Regulatory Information
General Safety Considerations
Servicing
These servicing instructions are for use by qualified personnel only.
To avoid electrical shock, do not perform any servicing unless you
are qualified to do so.
Danger of explosion if battery is incorrectly replaced. Replace only
with the same or equivalent type recommended. Discard used
batteries according to local ordinances and/or manufacturer’s
instructions.
Procedures described in this document may be performed with
power supplied to the product while protective covers are removed.
Energy available at many points may, if contacted, result in personal
injury.
Do not operate the analyzer with the outer cover removed for more than
30 minutes, as this could cause the analyzer to overheat which could
result in costly damage.
No operator serviceable parts inside. Refer servicing to qualified
personnel. To prevent electrical shock, do not remove covers.
The opening of covers or removal of parts may expose dangerous
voltages. Disconnect the instrument from all voltage sources while
it is being opened.
The detachable power cord is the instrument disconnecting device.
It disconnects the mains circuits from the mains supply before other
parts of the instrument. The front panel switch is only a standby
switch and is not a LINE switch (disconnecting device).
There are no replaceable fuses in the mains input or within the power
supply assembly.
Keysight personnel: after calibration is completed, attach four “calibration
void if seal broken” stickers to the PNA as shown in Figure 1-1.

1-6 Keysight N5244B/45B Service Guide
Safety and Regulatory Information
General Safety Considerations
1-
Figure 1-1 Location of Calibration Stickers on PNA

Keysight N5244B/45B Service Guide 1-7
Safety and Regulatory Information
Electrostatic Discharge Protection
Electrostatic Discharge Protection
Protection against electrostatic discharge (ESD) is essential while removing
assemblies from or connecting cables to the network analyzer. Static
electricity can build up on your body and can easily damage sensitive internal
circuit elements when discharged. Static discharges too small to be felt can
cause permanent damage. To prevent damage to the instrument:
—always have a grounded, conductive table mat in front of your test
equipment.
—always wear a grounded wrist strap, connected to a grounded conductive
table mat, having a 1 MΩresistor in series with it, when handling
components and assemblies or when making connections.
—always wear a heel strap when working in an area with a conductive floor. If
you are uncertain about the conductivity of your floor, wear a heel strap.
—always ground yourself before you clean, inspect, or make a connection to
a static-sensitive device or test port. You can, for example, grasp the
grounded outer shell of the test port or cable connector briefly.
—always ground the center conductor of a test cable before making a
connection to the analyzer test port or other static-sensitive device. This
can be done as follows:
1. Connect a short (from your calibration kit) to one end of the cable to
short the center conductor to the outer conductor.
2. While wearing a grounded wrist strap, grasp the outer shell of the
cable connector.
3. Connect the other end of the cable to the test port and remove the
short from the cable.
Figure 1-2 shows a typical ESD protection setup using a grounded mat and
wrist strap. Refer to “ESD Supplies” on page 6-304 for part numbers.

1-8 Keysight N5244B/45B Service Guide
Safety and Regulatory Information
Electrostatic Discharge Protection
1-
Figure 1-2 ESD Protection Setup