Keysight Technologies M937 A Series User manual

Service Guide
Keysight M937xA PXIe 
Vector Network Analyzer 
Modules
M9370A, 300 kHz to 4 GHz
M9371A, 300 kHz to 6.5 GHz
M9372A, 300 kHz to 9 GHz
M9373A, 300 kHz to 14 GHz
M9374A, 300 kHz to 20 GHz
M9375A, 300 kHz to 26.5 GHz

Notices
© Keysight Technologies, Inc.
2014-2015
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 Acknowledgments
Manual Part Number
M9370-90004
Print Date
July 2015
Supersedes: August 2014
Published 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 hard ware 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.
Restricted Rights Legend
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
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
Where to Find the Latest Information
For the latest information about these products, including the M937xA Help System, instrument software upgrades,
application information, and product information, browse to one of the following URLs:
http://na.support.keysight.com/pxi
http://www.keysight.com/find/pxi
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
Safety and regulatory information can be found in the Startup Guide, available online at:
http://literature.cdn.keysight.com/litweb/pdf/M9370-90001.pdf
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://na.support.keysight.com/pxi/firmware

Contents
Keysight M937xA PXIe Service Guide 4
1. General Product Information
Information in This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Chapter 1 at-a-Glance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Keysight Support, Services, and Assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Service and Support Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Contacting Keysight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Shipping Your Network Analyzer for Service or Repair . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Error Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Using Error Terms as a Diagnostic Tool. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Performing Measurement Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Using Flowgraphs to Identify Error Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Accessing Error Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
Manual Access to Error Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Programmatic Access to Error Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Error Term Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Option Enable Utility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
Accessing the Option Enable Utility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
Enabling or Removing Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
Changing a Serial Number. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
Firmware Upgrades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
How to Check the Current Firmware Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
Downloading from the Internet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
2. Tests, Adjustments, and Troubleshooting
Information in This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Chapter 2 at-a-Glance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Before You Begin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Get the Required Service Test Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Verify the Operating Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Protect Against Electrostatic Discharge (ESD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Allow the Analyzer to Warm Up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Review the Principles of Connector Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
About System Verification and Performance Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
System Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Instrument Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
System Verification Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
Performance Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
Certificate of Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
ANSI/NCSL Z540.3-2006 and ISO/IEC 17025 Verification . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

5 Keysight M937xA PXIe Service Guide
Contents
Non-Standards Compliant Verification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11
Preliminary Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
The Operator’s Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12
The Test Port Cable Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14
System Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20
What the System Verification Verifies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20
Measurement Uncertainty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20
Measurement Traceability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22
Performing System Verification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23
Performance Tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-30
Power Measurement Receiver System (PNAasPowerMeter) . . . . . . . . . . . . . . . . . . . . . 2-30
Source Power Accuracy Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-31
Source Maximum Power Output Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33
Source Power Linearity Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35
Frequency Accuracy Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-36
Trace Noise Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37
Receiver Compression Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-38
Noise Floor Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-40
Calibration Coefficients Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-42
Dynamic Accuracy Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-43
Adjustments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45
10 MHz Frequency Reference Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45
Source Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-46
Receiver Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-47
Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-48
Check the Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-48
3. Replaceable Parts and Connector Replacement Procedure
Information in This Chapter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-
1
Chapter 3 at-a-Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Replaceable Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Connector Replacement Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
Parts Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
-
3
Tools Required. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-
3
Removal Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
Replacement Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

1
General Product Information
Information in This Chapter
Keysight M937xA PXIe Service Guide
1 General Product Information
Information in This Chapter
Chapter 1 at-a-Glance
Section Title Summary of Content
Maintenance Cleaning instructions for the external surfaces
of your network analyzer.
Hyperlink to online information on connector
care.
Keysight Support, Services,
and Assistance
Hyperlink for Contacting Keysight.
How to get information on service and support
options available.
Important information about shipping your
module to Keysight for service or repair.
Error Terms How to use error term data as a diagnostic
tool.
Option Enable Utility How to use the Option Enable Utility to enable
or remove options, and install or change a
serial number.
Firmware Upgrades How to get firmware upgrades.

1-2 Keysight M937xA PXIe Service Guide
General Product Information
Maintenance
1-
Maintenance
Physical
Maintenance
To remove dirt or dust from the external case of the network analyzer, clean
the case using a dry or slightly dampened cloth only.
Electrical
Maintenance
For online information on connector care, go to
http://na.support.keysight.com/pna/connectorcare/Connector_Care.htm.
To prevent electrical shock, remove analyzer module from chassis
slot for cleaning. Use a dry cloth or one slightly dampened with
water to clean the external case parts. Do not attempt to clean
internally.

Keysight M937xA PXIe Service Guide 1-3
General Product Information
Keysight Support, Services, and Assistance
Keysight Support, Services, and Assistance
Information on the following topics is included in this section.
-Service and Support Options
-Contacting Keysight
-Shipping Your Network Analyzer for Service or Repair
Service and Support Options
The network analyzer’s standard warranty is a 3-year return to Keysight
Technologies service warranty.
Contacting Keysight
Assistance with test and measurement needs and information on finding a
local Keysight office are available on the Web at: www.keysight.com/find/assist. If
you do not have access to the Internet, please contact your Keysight field engineer.
Shipping Your Network Analyzer for Service or Repair
Should it become necessary to return a network analyzer for repair or service,
follow the steps below:
1. Review the warranty information shipped with your product.
2. Contact Keysight to obtain a Return Material Authorization (RMA) and
return address. For assistance finding Keysight contact information, go to
www.keysight.com/find/assist (worldwide contact information for repair and
service).
3. Write the following information on a tag and attach it to the network
analyzer.
- Name and address of owner. A P.O. box is not acceptable as a return
address.
There are many other repair and calibration options available from the
Keysight Technologies support organization. These options cover a range
of service agreements with varying response times. Contact Keysight for
additional information on available service agreements for this product.
Refer to Contacting Keysight.
In any correspondence or telephone conversation, refer to the Keysight
product by its model number and full serial number. With this information,
the Keysight representative can determine whether your product is still
within its warranty period.

1-4 Keysight M937xA PXIe Service Guide
General Product Information
Keysight Support, Services, and Assistance
1-
- network analyzer serial numbers. The serial number label is located on
the side panel of the module. The serial number can also be read from
the Soft Front Panel (SFP) interface, after the hardware is installed.
- Description of the failure or service required.
4. On the shipping label, write ATTENTION REPAIR DEPARTMENT and the
RMA number.
5. Ship the analyzer module using the original packaging materials. Shipping
the analyzer module in anything other than the original packaging may
result in non-warranted damage.

Keysight M937xA PXIe Service Guide 1-5
General Product Information
Error Terms
Error Terms
Using Error Terms as a Diagnostic Tool
By examining error terms, you can monitor system performance for preventive
maintenance and troubleshooting purposes.
The magnitude and shape of the error terms are affected by:
- calibration kit devices
-cables
-adaptersandaccessories
- test port connectors
Calibration kit devices, cables, adapters and accessories are the most common
cause of error term anomalies. Make sure of the following:
- Connectors must be clean, gaged, and within specification.
- Use proper connection technique during measurement and calibration. For
online information on connector care, go to
http://na.support.keysight.com/pna/connectorcare/Connector_Care.htm, or to the
calibration kit’s user’s and service manual.
Preventive Maintenance
If you print or plot the error terms at set intervals (weekly, monthly, etc), you
can compare current error terms to these records. A stable system should
generate repeatable error terms over long intervals, (for example, six months).
Look for the following:
- A long-term trend often reflects drift, connector and cable wear, or gradual
degradation, indicating the need for further investigation and preventive
maintenance. Yet, the system may still conform to specifications. The cure is
often as simple as cleaning and gaging connectors and cables.
- A sudden shift in error terms may indicate the need for troubleshooting.
Troubleshooting
Refer to error term descriptions in “Error Term Data” on page 1-9.
Always suspect calibration devices, cables, or improper connector
maintenance as the primary cause of an error term anomaly.

1-6 Keysight M937xA PXIe Service Guide
General Product Information
Error Terms
1-
Performing Measurement Calibration
1. Connect a test cable to Port 2.
2. Perform a full 2-port calibration. Refer to Help if necessary.
Using Flowgraphs to Identify Error Terms
Flowgraphs are a graphical representation of signal flow through the
measurement path. The flowgraphs in Figure 1-1 and Figure 1-2 illustrate the
error terms associated with measurement calibration for 1-port and 2-port
configurations respectively.
Figure 1-1 Flowgraph of 1-Port Error Terms for Port 1
Where:
E = Error term
Subscript:
D = Directivity
S = Source Match
R = Reflection Tracking
The error terms are the same for a 1-port measurement on Port 2 (S22).
Follow ESD-safe practices when working with the network analyzer. For
more information, refer to Chapter 1 in the M937xA Startup Guide,
viewable online at
http://literature.cdn.keysight.com/litweb/pdf/M9370-90001.pdf

Keysight M937xA PXIe Service Guide 1-7
General Product Information
Error Terms
Figure 1-2 Flowgraph of 2-Port Error Terms
Where:
E = Error term
1st Subscript:
D = Directivity
S = Source Match
R = Reflection Tracking
X = Crosstalk (Isolation)
L = Load Match
T = Transmission Tracking
2nd Subscript:
F = Forward measurement (Port 1 to Port 2)
R = Reverse measurement (Port 2 to Port 1)
Accessing Error Terms
Error terms can be accessed either manually or programmatically:
Manually
“Soft Front Panel Access to Error Terms” on page 1-8

1-8 Keysight M937xA PXIe Service Guide
General Product Information
Error Terms
1-
Programmatically
“GPIB Access to Error Terms” on page 1-8
Manual Access to Error Terms
Soft Front Panel Access to Error Terms
To access the error terms from the soft front panel, perform the following
steps:
1. In the System menu, click Response > Cal > ManageCals > Cal Set Viewer.
The Cal Set Viewer tool bar appears directly above the trace window.
2. In the Cal Sets drop-down list, select the desired cal set.
3. Click Standards to view the raw measurement data of the Standard (ONLY
available with Unguided Cal (not ECal or Guided Cal)), or click Error Terms
to view the corrected error term data.
4. Use the Error Term box drop-down list to select an error term or standard to
view.
5. Select the Enable check box to view the data on the PC display.
6. Compare the displayed measurement trace to the equivalent data that
starts in “Error Term Data” on page 1-9, or to previously measured data, or
to the uncorrected performance specifications listed in Table 1-1 on
page 1-9.
7. Print numerical data or print a plot of the measurement results.
Programmatic Access to Error Terms
GPIB Access to Error Terms
You can access error terms by way of GPIB with Standard Commands for
Programmable Instruments (SCPI).
For more information on GPIB and SCPI, refer to Help. Search for keywords
“error, systematic” in the index.
Ensure the calibration correction is active by making sure that the check
box for Correction on/OFF has been selected.

Keysight M937xA PXIe Service Guide 1-9
General Product Information
Error Terms
Error Term Data
The error term descriptions in this section include the following information:
- a table of error terms
- description and significance of each error term
- measurements affected by each error term
- typical cause of failure for each error term
The same description applies to both the forward (F) and reverse (R) terms.
If Error Terms Seem Worse than Expected
To verify that the system still conforms to specifications, perform a system
verification. Refer to “System Verification” on page 2-20.
Data are listed here as a convenience only. Detailed instrument
specifications are in the Data Sheet, viewable online at
http://literature.cdn.keysight.com/litweb/pdf/M9370-90002.pdf
Table 1-1 Error Term Dataa
Frequency Range Directivity Source
match
Load match Crosstalkb
300 kHz to < 2 MHz 9 9 9 97
2 MHz to 1 GHz 21 19 21 95
> 1 to 2 GHz 21 20 19 123
> 2 to 4 GHz 21 20 15 121
> 4 to 6.5 GHz 20 15 11 121
> 6.5 to 9 GHz 11 11 9 119
> 9 to 14 GHz 9 9 7 110
> 14 to 20 GHz 4 6 6 98
> 20 to 24 GHz 3 5 4 82
a. The data in this table are uncorrected system performance. The values apply over an envi-
ronmental temperature range of 25 °C ±5 °C, with less than 1 °C deviation from the cali-
bration temperature.
b. All crosstalk values are typical.

1-10 Keysight M937xA PXIe Service Guide
General Product Information
Error Terms
1-
Directivity (EDF and EDR)
EDF and EDR are the uncorrected forward and reverse directivity error terms of
the system. The directivity error of the test port is determined by measuring the
S11 and S22 reflection of the calibration kit load. The load has a much better
return loss specification than does the uncorrected text port. Therefore, any
power detected from this measurement is assumed to be from directivity error.
The measurements most affected by directivity errors are measurements of low
reflection devices.
Typical Cause of Failure
The calibration kit load is the most common cause of directivity specification
failure.
If the load has been gaged and its performance independently verified, the
analyzer requires repair. Refer to “Shipping Your Network Analyzer for Service
or Repair” on page 1-3.
Source Match (ESF and ESR)
ESF and ESR are the forward and reverse uncorrected source match terms of
the driven port. They are obtained by measuring the reflection (S11, S22) of an
open, and a short that are connected directly to the ports. Source match is a
measure of the match of the coupler, as well as the match between all
components from the source to the output port.
The measurement most affected by source match errors are reflection and
transmission measurements of highly reflective DUTs.
Typical Cause of Failure
The calibration kit open or short is the most common cause of source match
specification failure.
If the open or short performance are independently verified, the analyzer
requires repair. Refer to “Shipping Your Network Analyzer for Service or
Repair” on page 1-3.
Load Match (ELF and ELR)
Load match is a measure of the impedance match of the test port that
terminates the output of a 2-port device. The match of test port cables is
included in this response. Load match error terms are characterized by
measuring the S11 and S22 responses of a “thru” configuration during the
calibration procedure.
The measurements most affected by load match errors are all transmission
measurements, and reflection measurements of a low insertion loss, 2-port
device, such as an airline.

Keysight M937xA PXIe Service Guide 1-11
General Product Information
Error Terms
Typical Cause of Failure
The calibration kit load or a bad “thru” cable is the most common cause of load
match specification failure.
If the load and “thru” cable performance are independently verified, the
analyzer requires repair. Refer to “Shipping Your Network Analyzer for Service
or Repair” on page 1-3.
Reflection Tracking (ERF and ERR)
Reflection tracking is the difference between the frequency response of the
reference path (R1 or R2 path) and the frequency response of the reflection test
path (A or B input path). These error terms are characterized by measuring the
reflection (S11, S22) of the open and the short during the measurement
calibration.
All reflection measurements are affected by the reflection tracking errors.
Typical Cause of Failure
The calibration kit open or short is the most common cause of reflection
tracking specification failure.
If the open or short performance has been independently verified, the analyzer
requires repair. Refer to “Shipping Your Network Analyzer for Service or
Repair” on page 1-3.
Transmission Tracking (ETF and ETR)
Transmission tracking is the difference between the frequency response of the
reference path (including the R input) and the frequency response of the
transmission test path (including the A or B input) while measuring
transmission. The response of the test port cables is included. These terms are
characterized by measuring the transmission (S21, S12) of the “thru”
configuration during the measurement calibration.
All transmission measurements are affected by the transmission tracking
errors.
Typical Cause of Failure
The test port cable is the most common cause of transmission tracking
specification failure.
If the test port cable performance has been independently verified, the
analyzer requires repair. Refer to “Shipping Your Network Analyzer for Service
or Repair” on page 1-3.
Isolation (EXF and EXR)
Isolation, or crosstalk, is the uncorrected forward and reverse isolation error
terms that represent leakage between the test ports and the signal paths. The
isolation error terms are characterized by measuring the transmission (S21,

1-12 Keysight M937xA PXIe Service Guide
General Product Information
Error Terms
1-
S12) with loads attached to both ports during the measurement calibration.
Isolation errors affect transmission measurements primarily where the
measured signal level is very low.
The measurements most affected by isolation error terms are DUTs with large
insertion loss. Since these terms are low in magnitude, they are usually noisy
(not very repeatable).
Typical Cause of Failure
A loose cable connection or leakage between components is the most likely
cause of isolation problems.
After verifying the cable and its connections, the analyzer requires repair. Refer
to “Shipping Your Network Analyzer for Service or Repair” on page 1-3.

Keysight M937xA PXIe Service Guide 1-13
General Product Information
Option Enable Utility
Option Enable Utility
Accessing the Option Enable Utility
To start the option enable utility:
-ClickUtility > System > Service > Option Enable.
- The dialog box illustrated in Figure 1-3 is displayed.
Figure 1-3 Option Enable Dialog Box
Enabling or Removing Options
Software options add features or functionality to the analyzer without the need
for additional hardware. These options are enabled using a special keyword.
They are enabled using the option enable utility.
To enable or remove an option:
1. Start the option enable utility. Refer to Accessing the Option Enable Utility.
2. Click the arrow in the Select Desired Option box. A list of available options,
similar to the following list, will appear.
010 Time Domain
551 Multiport
Options require a license key that is provided by Keysight. If you do not
have the required license key, contact Keysight for assistance. Refer to
“Contacting Keysight” on page 1-3.

1-14 Keysight M937xA PXIe Service Guide
General Product Information
Option Enable Utility
1-
102 Advanced Features
??? Enter Unlisted Option
3. Click on the option that you wish to either enable or remove, and then click
Enable or Remove, whichever is appropriate.
4. If the desired option is not available in the list (unlikely to occur), select
Enter Unlisted Option. A dialog box appears that will allow you to enter the
option number. Enter the option number and follow the instructions on the
display.
Changing a Serial Number
1. To change a serial number, select Change Serial from the Option Enable
menu bar (refer to Figure 1-3 on page 1-13). The current serial number is
displayed in the Change Serial Number dialog box. If no serial number has
previously been entered, the word “NONE” will be displayed.
2. VERY CAREFULLY, type the new serial number into the space provided.
3. Type the Clear Code keyword into the space provided.
4. Click Change.
5. Note the serial number displayed in the Option Enable dialog box, then
click Exit.
6. If the wrong serial number is displayed, obtain another clear code from
Keysight, and repeat the steps above.
To change an incorrect serial number, a clear code keyword is required.
Contact Keysight to obtain the clear code keyword. You must provide the
current serial number, as displayed in the Change Serial Number dialog
box (see Step 1 below). Refer to “Contacting Keysight” on page 1-3.
Use extreme care when entering the serial number, as only one attempt is
allowed.

Keysight M937xA PXIe Service Guide 1-15
General Product Information
Firmware Upgrades
Firmware Upgrades
How to Check the Current Firmware Version
1. With the Network Analyzer application running, click Help > About
Network Analyzer. A dialog box showing the current installed Application
Code Version is displayed.
2. To determine if a firmware update is available, proceed to Downloading
from the Internet below.
Downloading from the Internet
If your network analyzer is connected to the Internet, there are two methods
available for checking the availability of, and downloading, new firmware.
- Download directly from http://na.support.keysight.com/pxi/firmware.
• On the System menu, click Service > AgileUpdate. AgileUpdate compares
the firmware revision currently installed in your network analyzer to the
latest version available and assists you in downloading and installing the
most recent version.