Keysight Technologies N5251A Series User manual

INSTALLATION AND SERVICE GUIDE
)
Keysight Technologies
N5251A PNA Series 2-Port and
Microwave Network Analyzer
System
(10 MHz - 110 GHz)
Use this manual in conjunction with the following
documents:
- PNA Series Network Analyzer Embedded Help
System
(Online at: https://support.keysight.com)
- PNA Series Network Analyzer Installation and
Quick Start Guide
Part Number E8356-90001
- N5227A PNA Series Microwave Network
Analyzer Service Guide
Part Number N5227-90001
- N5261A and N5262A Millimeter Head
Controller User's and Service Guide Part
Number: N5262-90001
This is the Service Guide for the N5251A 2- and 4-Port Series Microwave Network Analyzer Systems.

i Installation and Service Guide N5251-90001
Notices
© Keysight Technologies, Inc.
2012-2023
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
N5251-90001
Edition
Edition 1, January 2023
Supersedes: February 2017
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 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.
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
commercial license, which is
embodied in its End User License
Agreement (EULA), a copy of
which can be found at
http://www.keysight.com/find/sweula
The license set forth in the EULA
represents the exclusive authority
by which the U.S. government
may use, modify, distribute, or
disclose the Software. The EULA
and the license set forth therein,
does not require or permit,
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
government rights in excess of
these rights customarily provided
to the public to use, modify,
reproduce, release, perform,
display, or disclose commercial
computer software or
commercial computer software
documentation. No additional
government requirements
beyond those set forth in the
EULA shall apply, except to the
extent that those terms, rights, or
licenses are explicitly required
from all providers of commercial
computer software pursuant to
the FAR and the DFARS and are
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.

Installation and Service Guide N5251-90001 ii
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Assistance
Product maintenance agreements and other customer assistance agreements are available
for Keysight Technologies, Inc. products. For information about these agreements and
for other assistance, contact Keysight. Refer to “Contacting Keysight” on page 5-4.
Safety and Regulatory Information
The safety and regulatory information pertaining to this product is located in Chapter 1,
“Safety and Regulatory Information”.
Printing Copies of the Documentation from the Web
To print copies of documentation from the Web, download the PDF file from the
Keysight web site at: www.keysight.com

iii Installation and Service Guide N5251-90001

Contents
Installation and Service Guide N5251-90001 Contents-1
1 Safety and Regulatory Information
Safety Symbols. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
General Safety Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Safety Earth Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Before Applying Power. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Electrostatic Discharge Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
Regulatory Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
Instrument Markings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Lithium Battery Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
EMC and Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
2System Description
N5251A Network Analyzer System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
Basic System Measurement Configurations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Coaxial Measurement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
Wafer Probe Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
N5261A and N5262A Millimeter Head Controllers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Millimeter-Wave Test Head Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Theory of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
3 System Installation
Receiving the System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
The System as Shipped. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
Keysight Technologies Customer Engineering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
System Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
Site Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
Power Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
Environmental Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6
Protect Against Electrostatic Discharge (ESD). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
Review the Principles of Connector Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
Space Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
PNA, Controller, and Test Head Module Interconnections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
Mount PNA on Top of Controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
Rear Panel Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
Front Panel Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
Configuring the PNA Software for the N5251A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-16
4 System Specifications
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
System Specifications (typical) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
N5227A Rear Panel Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
N5251A Test Head Bias-Tees Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Test Head Module Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

Contents-2 Installation and Service Guide N5251-90001
Contents
Physical Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
Electrical Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
Caring for Waveguide (WG) Interfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-2
Principles of Connector Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-3
Keysight Support, Services, and Assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
Service and Support Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
Contacting Keysight. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
Shipping an Item to Keysight for Service or Repair. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
6 Performance Tests and Checks
System Preparation and Analyzer Warm Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
Torquing Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
Long Term Storage of Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-2
Protect Against Electrostatic Discharge (ESD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
Review the Principles of Connector Care. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3
System Check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
System Performance Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
When to Verify . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-6
Materials Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
General Preparation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Verification Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Verification Results Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-11
Interpreting the Verification Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-15
Improving the Verification Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-16
Saving Verification Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-16
7 Replaceable Parts
Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
Replaceable Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3
5 Maintenance and Support
Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

Installation and Service Guide N5251-90001 1-1
1 Safety and Regulatory Information

1-2 Installation and Service Guide N5251-90001
Safety and Regulatory Information
Safety Symbols
PNA Series Microwave Network Analyzer System
N5251A
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.
General Safety Considerations
Safety Earth Ground
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.
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.
Before Applying Power
Make sure that the analyzer line voltage selector switch is set to the voltage of
the power supply and the correct fuse is installed.
If this product is to be energized via an autotransformer make sure the common
terminal is connected to the neutral (grounded side of the mains supply).
This product is designed for use in Installation Category II and Pollution Degree 2.
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.

Installation and Service Guide N5251-90001 1-3
PNA Series Microwave Network Analyzer System
N5251A
Safety and Regulatory Information
General Safety Considerations
The opening of covers or removal of parts may expose dangerous voltages.
Disconnect the instrument from all voltage sources while it is opened.
Danger of explosion if battery is incorrectly replaced. Replace only with
the same or equivalent type recommended. Discard used batteries
according to 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.
The power cord is connected to internal capacitors that may remain live for
10 seconds after disconnecting the plug from its power supply.
For continued protection against fire hazard, replace line fuse only with same
type and rating. The use of other fuses or material is prohibited.
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).

1-4 Installation and Service Guide N5251-90001
Safety and Regulatory Information
Electrostatic Discharge Protection
PNA Series Microwave Network Analyzer System
N5251A
Electrostatic Discharge Protection
Protection against electrostatic discharge (ESD) is essential while removing assemblies from or
connecting cables to the system components. 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 M resistor 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 1-1 shows a typical ESD protection setup using a grounded mat and wrist strap.
Figure 1-1 ESD Protection Setup

Installation and Service Guide N5251-90001 1-5
PNA Series Microwave Network Analyzer System
N5251A
Safety and Regulatory Information
Regulatory Information
Regulatory Information
This section contains information that is required by various government regulatory
agencies.

1-6 Installation and Service Guide N5251-90001
PNA Series Microwave Network Analyzer System
N5251A
Safety and Regulatory Information
Regulatory Information
Instrument Markings
IP 2 0
The instruction documentation symbol. The product is marked with this symbol when it is
necessary for the user to refer to the instructions in the documentation.
The AC symbol indicates the required nature of the line module input power.
This symbol indicates separate collection for electrical and electronic equipment, mandated
under EU law. All electric and electronic equipment are required to be separated from normal
waste for disposal (Reference WEEE Directive).
This symbol indicates that the power line switch is ON.
This symbol indicates that the power line switch is in the STANDBY position.
This symbol indicates that the power line switch is in the OFF position.
This symbol is used to identify a terminal which is internally connected to the product frame or
chassis.
The CE mark is a registered trademark of the European Community.
The CSA mark is a registered trademark of the CSA International.
This is a symbol of an Industrial Scientific and Medical Group 1Class A product (CISPR 11,
Clause 5).
This is a marking to indicate product compliance with the Canadian Interference-Causing
Equipment Standard (ICES-001). Cet appareil ISM est conforme à la norme NMB du Canada.
Direct Current.
The instrument has been designed to meet the requirements of IP 2 0 for egress and
operational environment.
The RCM mark is a registered trademark of the Australian Communications and Media
Authority.
Indicates the time period during which no hazardous or toxic substance elements are
expected to leak or deteriorate during normal use. Forty years is the expected useful life of
the product.
This symbol on all primary and secondary packaging indicates compliance to China standard
GB 18455-2001.
South Korean Certification (KC) mark; includes the marking's identifier code which follows the
format: MSIP-REM-YYY-ZZZZZZZZZZZZZZ.
ICES/NMB-001

Installation and Service Guide N5251-90001 1-7
PNA Series Microwave Network Analyzer System
N5251A
Safety and Regulatory Information
Regulatory Information
Lithium Battery Disposal
If the battery on the network analyzer’s CPU board needs to be disposed of, dispose of it in
accordance with your country’s requirements. If required, you may return the battery to Keysight
Technologies for disposal. For assistance refer to “Contacting Keysight” on page 5-4.

Safety and Regulatory Information
Regulatory Information
PNA Series Microwave Network Analyzer System
N5251A
EMC and Safety Information
EMC Information
Complies with European EMC Directive 2014/30/EU
•IEC/EN 61326-2-1
•CISPR Pub 11 Group 1, Class A
•AS/NZS CISPR 11
•ICES/NMB-001
This ISM device complies with Canadian ICES-001. Cet appareil ISM est conforme a la norme
NMB-001 du Canada.
Safety
Complies with European Low Voltage Directive 2006/95/EC
•IEC/EN 61010-1, 2nd Edition
•Canada: CSA C22.2 No. 61010-1
•USA: UL std no. 61010-1, 2nd Edition
•German Acoustic statement
Acoustic noise emission
LpA <70 dB
Operator position
Normal position
Per ISO 7779
Geraeuschemission
LpA <70 dB
Am Arbeitsplatz
Normaler Betrieb
Nach DIN 45635 t.19
1-8Installation and Service Guide N5251-90001

Installation and Service Guide N5251-90001 2-1
2 System Description

2-2 Installation and Service Guide N5251-90001
System Description
N5251A Network Analyzer System
PNA Series Microwave Network Analyzer System
N5251A
N5251A Network Analyzer System
The N5251A is a 2-port or 4-port vector network analyzer system with an extremely wide
frequency range of 10 MHz to 110 GHz. The N5251A uses the same 1.0 mm test port
connections throughout its entire range of test frequencies. It is never necessary to make and
break connections to complete a test.
The illustration below shows the N5251A configured for coaxial measurement. The system can
also be configured for on-wafer measurement using a wafer probe test station.
Figure 2-1 N5251A 4-Port System

Installation and Service Guide N5251-90001 2-3
System Description
N5251A Network Analyzer System
PNA Series Microwave Network Analyzer System
N5251A
Options

2-4 Installation and Service Guide N5251-90001
System Description
Basic System Measurement Configurations
PNA Series Microwave Network Analyzer System
N5251A
Basic System Measurement Configurations
The N5251A can be used in either of two basic configurations, depending on how the test ports
are connected to the device under test (DUT): coaxial measurement configuration or wafer
probe measurement configuration.
Input power to the test ports must not exceed +27 dBm. Input power in excess
of this level will damage expensive components. Observe proper precautions,
especially when measuring amplifiers with gains of 20 dB or greater.
Coaxial Measurement
This configuration is used when the DUT has coaxial connectors. The N5251A test ports have 1.0
mm coaxial connectors, and are designed to cover a frequency range of 10 MHz to 110 GHz.
In this configuration, the test head modules are placed on a work bench in front of the millimeter
head controller.
The DUT is normally connected to the test ports by way of a 1.0 mm coaxial cable (test port
cable). Connect the DUT to Port 1 (left test head module) directly, and to Port 2 (right test head
module) by way of a test cable. It is also possible to connect the DUT using a test port cable on
each test port, although this configuration will result in greater signal loss.
Do not attempt to connect a test device directly between the two 1.0 mm test
ports, without at least one test port cable. The test head modules will not move
freely enough to allow such a connection to be made safely.
Figure 2-2 on page 2-5 shows how the instruments are configured on a work bench for the
coaxial measurement configuration. The test head modules are placed on the bench top in
front of the PNA and controller.

Installation and Service Guide N5251-90001 2-5
PNA Series Microwave Network Analyzer System
N5251A
System Description
Basic System Measurement Configurations
Figure 2-2 Coaxial Measurement Configuration, 2-Port System
Wafer Probe Measurement
In this configuration, the test head modules are placed on X-Y-Z positioners that are mounted
to the wafer probe station. Each 1.0 mm test port is directly connected to a wafer probe.
assembly via a coaxial cable.
The wafer probe measurement configuration is not documented in thismanual.
For information about probing equipment and accessories, contact:
For additional information on DUT bias connections, refer to Table 4-4 on page 4-4,
Figure 4-1 on page 4-5, and Figure 4-2 on page 4-6.
Cascade Microtech, Inc.
9100 SW Gemini Drive
Beaverton, Oregon 97008,USA
Toll-free telephone: [phone]
Telephone: [phone]
Fax: [phone]
Web site:
www.cascademicrotech.com

2-6 Installation and Service Guide N5251-90001
System Description
N5261A and N5262A Millimeter Head Controllers
PNA Series Microwave Network Analyzer System
N5251A
N5261A and N5262A Millimeter Head Controllers
The N5261A and N5262A millimeter head controllers provide the test interface between the
millimeter-wave test head modules and the N5227A PNA series network analyzer.
The millimeter head controller, when used in conjunction with the millimeter-wave test head
modules and the PNA, provides all of the feature and functions of a full S-Parameter test set.
The millimeter head controller supplies RF and LO signals to the millimeter-wave test head
modules and returns the down converted reference and test IF signals to the PNA for processing
and display. The N5261A and N5262A millimeter head controllers also supply the +12 volt bias to
each millimeter-wave head module.
The front panels of the N5261A and N5262A millimeter head controllers are illustrated below.
For additional information, see the N5261A and N5262A User’s and Service Guide. If a printed
version of the manual is not available, refer to “Printing Copies of Documentation from the Web”
on page ii of this manual.
Figure 2-3 N5261A Millimeter Head Controller Front Panel
Figure 2-4 N5262A Millimeter Head Controller Front Panel