Keysight Technologies 8481A, 8480 Series, 8483A, 8485A, 8487A Operating And Service Manual

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Keysight 8480 Series Coaxial Power Sensors

Operating and Service Manual

Notices

CAUTION

WARNING

duced 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 as governed by United States and international copyright laws.

Manual Part Number

08481-90173

Edition

Edition 6, October 1, 2017

Printed in:

Printed in Malaysia

Published by:

Keysight Technologies Bayan Lepas Free Industrial Zone, 11900 Penang, Malaysia

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.

Declaration of Conformity

Declarations of Conformity for this product and for other Keysight products may be downloaded from the Web. Go to http://www.keysight.com/

go/conformity. You can then search by

product number to find the latest Declaration of Conformity.

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.

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 OF 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 SHALL CONTROL.

Safety Information

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.

2 Keysight 8480 Series Operating and Service Manual

Notice

Warranty

The information contained in this document is subject to change without notice.

Keysight Technologies makes no warranty of any kind with regard to this material, including but not limited to, the implied warranties of merchantability and fitness for a particular purpose. Keysight Technologies shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing, performance, or use of this material.

A copy of the specific warranty terms applicable to your Keysight Technologies product can be obtained from your local Sales and Service Office.

Keysight 8480 Series Operating and Service Manual 3

Manufacturer's Declaration

This statement is provided to comply with the requirements of the German Sound Emission Directive, from 18 January 1991.

This product has a sound pressure emission (at the operator position)

< 70 dB(A).

– Sound Pressure Lp < 70 dB(A).

– At Operator Position.

–Normal Operation.

– According to ISO 7779:1988/EN 27779:1991 (Type Test).

Hersteller-bescheinigung

Diese Information steht im Zusammenhang mit den Anforderungen der Maschinenlärminformationsverordnung vom 18 Januar 1991.

– Schalldruckpegel Lp < 70 dB(A).

– Am Arbeitsplatz.

–Normaler Betrieb.

– Nach ISO 7779:1988/EN 27779:1991 (Typprüfung).

4 Keysight 8480 Series Operating and Service Manual

Regulatory Markings

The CE mark is a registered trademark of the European Community. This CE mark shows that the product complies with all the relevant European Legal

Directives.

[a] The CE mark is only applicable for 8481D, 8487D and 8485D.

[a]

Sales and Technical Support

To contact Keysight for sales and technical support, refer to the support links on the following Keysight websites:

– www.keysight.com/find/powersensors

(product-specific information and support, software and documentation updates)

– www.keysight.com/find/assist

(worldwide contact information for repair and service)

Keysight 8480 Series Operating and Service Manual 5

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6 Keysight 8480 Series Operating and Service Manual

Notice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Manufacturer's Declaration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Hersteller-bescheinigung . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Regulatory Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Sales and Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

1Introduction

General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Instruments Covered by Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

8480 series, B-models information . . . . . . . . . . . . . . . . . . . . . . . . . .17

8480 series, Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Recommended Calibration Interval . . . . . . . . . . . . . . . . . . . . . . . . . . 21

8480 Series Power Sensor Specifications . . . . . . . . . . . . . . . . . . . . . . .23

Supplemental Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

Initial Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

Storage and Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

Operating Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

2 General Information

Connector Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40

Torque . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40

Performance Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

Voltage standing wave ratio (VSWR) and reflection coefficient (Rho)

performance verification test . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

Keysight 8480 Series Operating and Service Manual 7

Zero set performance verification . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Power linearity performance verification . . . . . . . . . . . . . . . . . . . . . 46

Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Replaceable Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

3Service

Principles of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Thermocouple sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Diode sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Troubleshooting - eliminating the power meter and sensor cable . 59

Troubleshooting - power sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

A1 Bulkhead (thermocouple sensors) . . . . . . . . . . . . . . . . . . . . . . . . 60

Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

A1 Bulkhead Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

A2 Power Sensor Board Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . 64

FET Balance Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Equipment Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Test Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

FET Balance Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Disassembly / Reassembly Procedures . . . . . . . . . . . . . . . . . . . . . . . . . 69

Disassembly Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Reassembly Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

A EPM Series Power Meter (E4418B) Modification

The Material and Tools Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Impact on Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Modification Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

B Bulkhead Assemblies

Bulkhead Parts Lists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

Bulkhead Exploded Graphics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

8 Keysight 8480 Series Operating and Service Manual

List of Figures

Figure 1-1 Example serial number . . . . . . . . . . . . . . . . . . . . . . . . .14

Figure 1-2 8480 Series power sensor simplified block diagram . . 16

Figure 1-3 Mechanical adapter (8483A Only) . . . . . . . . . . . . . . . . 19

Figure 1-4 8485A, 8485A-033, 8485D, 8485D-033 sensor

Figure 1-5 8487A power sensor with adapter . . . . . . . . . . . . . . . .21

Figure 1-6 Typical CAL FACTOR and SWR vs. Frequency . . . . . .31

Figure 1-7 Typical CAL FACTOR and SWR vs. Frequency (8485D) .

Figure 1-8 Typical CAL FACTOR and SWR vs. Frequency (8487D) .

Figure 1-9 Typical influence of temperature on sensitivity . . . . . .36

Figure 2-1 Zero set performance verification equipment setup . .45

Figure 2-2 DUT to power meter connection . . . . . . . . . . . . . . . . .45

Figure 2-3 Power linearity performance verification equipment

Figure 2-4 Illustrated major parts breakdown . . . . . . . . . . . . . . . . 51

Figure 3-1 Schematic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . .58

Figure 3-2 Example of an acceptable waveform . . . . . . . . . . . . . .67

Figure 3-3 Example of an unacceptable waveform . . . . . . . . . . . .68

Figure 3-4 Removing the power sensor’s cover . . . . . . . . . . . . . .70

Figure 3-5 Power sensor hardware locations . . . . . . . . . . . . . . . .71

Figure A-1 Remove screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75

Figure A-2 Remove the power meter handle . . . . . . . . . . . . . . . . .76

Figure A-3 Remove the power meter cover . . . . . . . . . . . . . . . . . .76

Figure A-4 Power meter with its cover removed . . . . . . . . . . . . . .77

Figure A-5 Remove three hold plugs . . . . . . . . . . . . . . . . . . . . . . . 77

Figure A-6 Holes in the rear panel . . . . . . . . . . . . . . . . . . . . . . . . .78

Figure A-7 Solder each wire onto the screw-fit BNC female

Figure A-8 Fit the three BNC connectors into the three holes in the

Figure A-9 Location to solder each wire . . . . . . . . . . . . . . . . . . . .80

Figure A-10 Different view of the modified Measurement PCB . . .80

accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47

connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78

rear panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79

Keysight 8480 Series Operating and Service Manual 9

Figure A-11 Label the BNC connectors with a permanent marker and

adhesive labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

Figure B-1 8481A and 8481B . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Figure B-2 8481A Option 001 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

Figure B-3 8482A and 8482B . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

Figure B-4 8481D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Figure B-5 8481H and 8482H . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

Figure B-6 8483A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

Figure B-7 8485A, 8485A Opt 033, 8485D, and 8485D Opt 033 . 96

Figure B-8 8487A and 8487D . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

10 Keysight 8480 Series Operating and Service Manual

List of Tables

Table 1-1 8480 Series power sensor dimensions (including the RF

connector) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Table 1-2 11708A 30 dB attenuator characteristics . . . . . . . . . .19

Table 1-3 Typical measurement uncertainties of Calibration Factor

(CF) data printed on the power sensor . . . . . . . . . .23

Table 1-4 Typical measurement uncertainties of Calibration Factor

(CF) data printed on the power sensor . . . . . . . . . .24

Table 1-5 25 Watt sensors, 1 mW to 25 W (0 dBm to +44 dBm) 25 Table 1-6 3 Watt sensors, 100 µW to 3 W (–10 dBm to +35 dBm)

26 Table 1-7 100 mW sensors, 1 µW to 100 mW (–30 dBm to +20

dBm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

Table 1-8 High sensitivity sensors, 100 pW to 10 µW (–70 dBm to

–20 dBm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

Table 1-9 Cal factor to dB conversion chart . . . . . . . . . . . . . . . .37

Table 2-1 Power sensor SWR and reflection coefficient . . . . . . .42

Table 2-2 Bulkhead assembly . . . . . . . . . . . . . . . . . . . . . . . . . . .52

Table 2-3 Power sensor board assemblies . . . . . . . . . . . . . . . . .52

Table 2-4 Common chassis components . . . . . . . . . . . . . . . . . . . 53

Table 2-5 Adapters and attenuators . . . . . . . . . . . . . . . . . . . . . .53

Table 2-6 Identification labels . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Table 2-7 Miscellaneous labels . . . . . . . . . . . . . . . . . . . . . . . . . .54

Table 3-1 Bulkhead assembly resistance . . . . . . . . . . . . . . . . . . .61

Table B-1 Bulkhead parts for the 8481A, 8481B, 8482B, and 8482B

models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84

Table B-2 Bulkhead parts for the 8481D model . . . . . . . . . . . . . . 85

Table B-3 Bulkhead parts for the 8481H and 8482H models . . .86

Table B-4 Bulkhead parts for the 8483A model . . . . . . . . . . . . . .87

Table B-5 Bulkhead parts for the 8485A and 8485D models . . . 88 Table B-6 Bulkhead parts for the 8487A and 8487D models . . . 89

Keysight 8480 Series Operating and Service Manual 11

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12 Keysight 8480 Series Operating and Service Manual

Keysight 8480 Series Coaxial Power Sensors Operating and Service Manual

1 Introduction

General Information 14 8480 Series Power Sensor Specifications 23 Installation 34 Operation 35

This Operating and Service Manual contains information about initial inspection, performance tests, adjustments, operation, troubleshooting and repair of the Keysight 8480 Series Coaxial Power Sensors.

1Introduction

General Information

Instruments Covered by Manual

A serial number label is attached to the power sensor. The serial number has two parts: the prefix (two letters and the first four numbers), and the suffix (the last four numbers). Refer to the Example Serial Number shown in Figure 1-1.

Figure 1-1 Example serial number

The two letters identify the country in which the unit was manufactured. "US" represents the USA and "MY" represents Malaysia. The four numbers of the prefix are a code identifying the date of a major design change incorporated in your power sensor. The four digit suffix is a sequential number and, coupled with the prefix, provides a unique identification for each unit produced.

When seeking information about your power sensor refer to the complete serial number and include the full prefix number and the suffix number.

For further information concerning a serial number, contact your nearest Keysight Technologies Sales and Service office.

Description

The 8480 series power sensors are used for measuring the average power supplied by an RF or microwave source or device-under-test (DUT). In use, the Power Sensor is connected to the RF or microwave source and to a compatible

14 Keysight 8480 Series Operating and Service Manual

Introduction 1

NOTE

power meter. Suitable and compatible power meters are the EPM series power meters (E4418B and E4419B), the EPM-P series power meters (E4416A and E4417A) and the E1416A VXI power meter. Discontinued and obsolete power meters that are compatible with the 8480 series sensors include the E4418A, E4419A, 435B, 436A, 437B, 438A and 70100A MMS power meter.

The 8480 series power sensors place a 50 ohm load on the RF or microwave source, except the 8483A which has a 75 ohm load. The power meter indicates the power dissipated in this load in mW or dBm.

The coaxial power sensors in the 8480 series measure power levels from -70 dBm to +44 dBm (100 pW to 25 W), at frequencies from 100 kHz to 50 GHz. To cover this wide dynamic power range, both thermocouple and diode power sensing elements are used. Both types of power sensing elements have a maximum 50 dB dynamic range. Thermocouple sensors have a square-law region from -30 dBm to +20 dBm, and with an attenuator can operate up to +44 dBm. There are three model types of thermocouple sensors in the 8480 series, covering the complete

-30 dBm to +44 dBm range.

– The A-models cover -30 dBm to +20 dBm.

– The H-models cover from -10 dBm to +35 dBm.

– The B-models cover from 0 dBm to +44 dBm.

Diode detectors (D-models) have the best sensitivity, having an operating range from -70 dBm to -20 dBm.

Calibration factor (CAL FACTOR) data is provided on a label attached to the power sensor's cover. Maximum uncertainties of the CAL FACTOR data are listed in the Specifications section in page 23. This calibration factor is used to adjust the power meter to suit the particular power sensor and frequency being measured.

For the B-models in the 8480 series, calibration factor data is valid only when the sensor is used with the supplied attenuator.

Keysight 8480 Series Operating and Service Manual 15

1Introduction

Input

Power Sensing

Element

Thermocouple or

Diode

Balanced Chopper

Thermistor

Cable

AC Signal

Feedback

Chop Signal

Autozero

Figure 1-2 8480 Series power sensor simplified block diagram

Figure 1-2 shows a basic power sensor block diagram for both thermocouple and

diode power sensing elements. From the RF or microwave signal input, both thermocouple and diode detector mounts generate very low voltages, (on the order of nV or µV). The dc voltage is proportional to the power from the RF or microwave source. As the dc voltage is a very low-level, it requires amplification before it can be transferred to the power meter on the standard cables.

The amplification is provided by an input amplifier assembly that consists of a balanced chopper (sampling gate) and an AC coupled low-noise amplifier. The dc voltage is routed on gold wires to the chopper circuit, which converts the low-level dc voltage to an ac voltage. To do this, the chopper is uses two field effect transistors (FET's) controlled by a 220 Hz square-wave generated by in the power meter (the Chop Signal). The result is an ac output signal proportional to the dc input. The ac signal is then amplified to a relatively high-level ac signal that can be routed to the power meter by standard cables.

The autozero signal removes residual error voltages when there is no input RF or microwave power connected to the sensor input, and temperature compensation is provided by a thermistor located in amplifier feedback path.

16 Keysight 8480 Series Operating and Service Manual

Introduction 1

CAUTION

Dimensions

The physical dimensions of the power sensors differ in the model types. This is due to the additional attenuation used to obtain the high power performance.

Table 1-1 8480 Series power sensor dimensions (including the RF connector)

8480 series power sensor models

A-models

B-models 83 mm x 114 mm x 248 mm (approx. 3.25 in. x 4.50 in. x 9.75 in.)

D-models

H-models 38 mm wide, 30 mm high, 149 mm long (1.5 in. x 1.2 in. x 5.9 in)

Dimensions

8481A, 8482A and 8483A: 38 mm wide, 30 mm high, 105 mm long (1.5 in. x 1.2 in. x 4.1 in) 8485A and 8487A: 38 mm wide, 30 mm high, 95 mm long (1.5 in. x 1.25 in. x 3.75 in.)

8481D and 8485D: 38 mm wide, 30 mm high, 102 mm long (1.5 in. x 1.2 in. x 4.02 in) 8487D: 38 mm wide, 30 mm high, 94 mm long (1.5 in. x 1.2 in. x 3.7 in)

Do not disassemble the power sensor. The 8480 series power sensors are static sensitive and can be easily damaged.

8480 series, B-models information

The 25 W (+44 dBm) power sensor is a calibrated combination of a 30 dB, 25 W attenuator assembly and a sensor assembly. The attenuator and sensor assemblies are calibrated as a set and must be used together if specified accuracies are to be obtained.

This combination is referred to as the power sensor.

Keysight 8480 Series Operating and Service Manual 17

1Introduction

CAUTION

WARNING

Removal of the D-ring that is on the sensor assembly WILL VOID THE WARRANTY. The input connector on the sensor has a D-ring to prevent the sensor from being connected to a high power source when its attenuator is not attached. The sensor must only be connected to the power meter for calibration or to the high power attenuator for RF measurement.

Safety Considerations

The warning that follows is related to possible personal injury.

The high power attenuator contains a substrate of beryllium oxide. Beryllium oxide in a powder form is a hazardous material and may be injurious to your health if inhaled. Do not perform any operation on the beryllium oxide that might generate dust. Defective attenuator should be returned to Keysight Technologies for proper disposal.

8480 series, Options

8485A and 8485D option 033

The 8485A and 8485D power sensors with option 033 are calibrated to measure power levels in the 50 MHz to 33 GHz frequency range. In all other respects, they are the same as their respective standard power sensor.

Accessories Supplied

Accessories are required to connect various power sensors to the power meter's 50 ohm, Power Reference (1 mW, 50 MHz) output connector (Type-N (f)).

8483A 75 ohm sensor

The 8483A sensor is supplied with an adapter, shown in . This accessory is a mechanical adapter only, not an impedance transformer, therefore an impedance mismatch exists that must be taken into consideration when calibrating the power meter and sensor. The REF CAL FACTOR, on the power sensor label, has been adjusted for the impedance mismatch. This REF CAL FACTOR, when used to calibrate any power meter, will allow calibration to 1.000 mW. The CAL FACTOR,

18 Keysight 8480 Series Operating and Service Manual

Introduction 1

CAUTION

from the data on the sensor label, should be used for any power measurements in a 75 ohm system at 50 MHz.

Remove the mechanical adapter from the power sensor before connecting the sensor to a 75 ohm source.

Figure 1-3 Mechanical adapter (8483A Only)

D-model 8480 series sensors (8481D, 8485D, 8485D-033 and 8487D)

D-model sensors are supplied with a 11708A 30 dB attenuator. To calibrate a D-model sensor, the 1 mW 50 MHz Power Reference supplied by the power meter must be reduced to 1µW. The reference attenuator provides the means to do this.

Table 1-2 11708A 30 dB attenuator characteristics

Characteristic Limits Comments

11708A accuracy at 50 MHz, 25 °C

Dimensions Length: 60 mm (2.4 in) Diameter: 20 mm (0.8 in)

30 ± 0.05 dB

Keysight 8480 Series Operating and Service Manual 19

Accuracy traceable to National Institute of Standards and Technology (NIST), with a temperature coefficient typically 0.003 dB per °C.

1Introduction

NOTE

The 11708A 30 dB attenuator is intended for use only at the 1 mW, 50 MHz power reference of the power meter. Its function as a calibration reference may be compromised if used for other purposes.

26.5 GHz and 33 GHz Frequency operation (8485A, 8485A-033, 8485D and 8485D-033)

8480 series sensors that operate up to 26.5 GHz and 33 GHz are fitted with APC-3.5mm (m) connectors as standard. To convert the APC-3.5mm (m) connector for calibration an adapter (APC-3.5 (f) to Type-N (m)) is included with the power sensors. Figure 1-4 shows the parts included with your power sensor.

The APC-3.5mm to Type-N adapter is intended for use only at the 1 mW, 50 MHz power reference of the power meter. Its function as a calibration reference may be compromised if used for other purposes.

Figure 1-4 8485A, 8485A-033, 8485D, 8485D-033 sensor accessories

20 Keysight 8480 Series Operating and Service Manual

Introduction 1

NOTE

50 GHz Frequency operation (8487A and 8487D)

8480 series sensors that operate up to 50 GHz are fitted with 2.4mm (m) connectors as standard. To convert the 2.4mm (m) connector for calibration, adapter (2.4mm (f) to Type-N (m)) is included with the power sensors (shown in

Figure 1-5).

The 2.4mm to Type-N adapter is intended for use only at the 1 mW, 50 MHz power reference of the power meter. Its function as a calibration reference may be compromised if used for other purposes.

Figure 1-5 8487A power sensor with adapter

Recommended Calibration Interval

Keysight Technologies recommends a one-year calibration cycle for the 8480 series power sensors.

Keysight 8480 Series Operating and Service Manual 21

1Introduction

Warranty

The 8480 series power sensors described in this manual are warranted and certified as indicated on the inside cover of this manual. Power sensors are warranted only when they are operated within their specifications, especially the maximum power handling capability. Any power sensor returned to Keysight Technologies under warranty will be examined carefully to determine if the failure was possibly due to improper use.

Do not open the power sensor. Any attempt to disassemble the power sensor will void the warranty.

22 Keysight 8480 Series Operating and Service Manual

8480 Series Power Sensor Specifications

NOTE

These specifications are valid with EPM and EPM-P Series of power meters.

The 8480 series thermocouple and diode power sensors provide accuracy, stability, and SWR over a wide range of frequencies (100 kHz to 50 GHz) and power levels (-70 dBm to +44 dBm)

Table 1-3 Typical measurement uncertainties of Calibration Factor (CF)

data printed on the power sensor

Frequency 25°C ± 3°C

8481A 8482A 8483A 8485A

100 kHz to 10 MHz - 0.87 1.59 -

10 MHz to 30 MHz 0.81 0.8 1.39 -

30 MHz to 500 MHz 0.78 0.8 1.41 1.29

500 MHz to 1.2 GHz 0.78 0.8 1.41 1.26

Introduction 1

1.2 GHz to 6 GHz 0.92 0.9 1.46 1.35

6 GHz to 14 GHz 1.16 - - 1.61

14 GHz to 18 GHz 1.59 - - 1.77

18 GHz to 26.5 GHz - - - 2.47

26.5 GHz to 33 GHz - - -

33 GHz to 34 GHz - - - -

34 GHz to 35 GHz - - - -

35 GHz to 40 GHz - - - -

40 GHz to 45 GHz - - - -

45 GHz to 50 GHz - - - -

[a] These uncertainties only apply to Option 033.

3.35

[a]

Keysight 8480 Series Operating and Service Manual 23

1Introduction

Tab le 1-4 Typical measurement uncertainties of Calibration Factor (CF) data printed on the

power sensor

Frequency

8487A 8481B 8482B 8481H 8482H 8487D 8485D 8481D

100 kHz to 10 MHz - - 1.50 - 0.91 - - -

10 MHz to 30 MHz - 1.48 1.44 0.86 0.81 - - 0.77

30 MHz to 500 MHz 1.38 1.48 1.51 0.88 0.92 1.33 1.24 0.81

500 MHz to 1.2 GHz 1.341.481.480.870.881.351.260.81

1.2 GHz to 6 GHz 1.411.541.530.980.951.411.350.97

6 GHz to 14 GHz 1.59 1.71 - 1.36 - 1.62 1.63 1.20

14 GHz to 18 GHz 1.69 1.99 - 1.71 - 1.73 1.83 1.72

18 GHz to 26.5 GHz 2.23 - - - - 2.25 2.45 -

26.5 GHz to 33 GHz 2.58 - - - - 2.55

33 GHz to 34 GHz 2.73 - - - - 3.08 - -

34 GHz to 35 GHz 2.73 - - - - 3.08 - -

35 GHz to 40 GHz 2.73 - - - - 3.08 - -

40 GHz to 45 GHz 3.67 - - - - 4.28 - -

45 GHz to 50 GHz 4.33 - - - - 4.72 - -

[a] These uncertainties only apply to Option 033

25°C ± 3°C

2.94

[a]

24 Keysight 8480 Series Operating and Service Manual

Table 1-5 25 Watt sensors, 1 mW to 25 W (0 dBm to +44 dBm)

Introduction 1

Model

Frequency range

Maximum SWR

Power linearity

[a]

power

Maximum

Connector type Weight

0°C to 35°C:

[b]

30W avg 35°C to 55°C:

25W avg

0.01 to 5.8 GHz: 500W pk

5.8 to 18 GHz: 125W pk

Type-N(m)

Net: 0.8 kg (1.75 lb)

Shipping: 1.5 kg (3.25 lb)

8481B

10 MHz to 18 GHz

10 MHz to 2 GHz: 1.10

2GHz to

12.4 GHz: 1.18

12.4 GHz to 18 GHz: 1.28

+35 dBm to +44 dBm: ±4%

500W.µs / pulse

0°C to 35°C:

[b]

8482B

100 kHz to 4.2 GHz

100 kHz to 2 GHz: 1.10

2GHz to

4.2 GHz: 1.18

+35 dBm to +44 dBm: ±4%

30W avg 35°C to 55°C:

25W avg

0.1 to 4,2 GHz: 500W pk

Type-N(m)

Net: 0.8 kg (1.75 lb)

Shipping: 1.5 kg (3.25 lb)

500W.µs / pulse

[a] Negligible deviation except for those power ranges noted.

[b] For pulses greater than 30 W, the maximum average power (Pa) is limited by the energy per pulse (E) in W.μs according to Pa = 30-0.02 E.

Keysight 8480 Series Operating and Service Manual 25

1Introduction

Tab le 1-6 3 Watt sensors, 100 µW to 3 W (–10 dBm to +35 dBm)

Model

8481H

8482H

[a] Negligible deviation except for those power ranges noted.

Frequency range

10 MHz to 18 GHz

100 kHz to 4.2 GHz

Maximum SWR

10 MHz to 8 GHz: 1.20

8GHz to

12.4 GHz: 1.25

12.4 GHz to 18 GHz: 1.30

100 kHz to

4.2 GHz: 1.20

Power

[a]

linearity

+25 dBm to +35 dBm: ±5%

Maximum power

3.5W avg, 100W pk

100W.µs / pulse

3.5W avg, 100W pk

100W.µs / pulse

Connector type Weight

Net: 0.2 kg

Type-N(m)

(0.38 lb) Shipping: 0.5 kg

(1.0 lb)

Net: 0.2 kg (0.38 lb)

Shipping: 0.5 kg (1.0 lb)

26 Keysight 8480 Series Operating and Service Manual

Table 1-7 100 mW sensors, 1 µW to 100 mW (–30 dBm to +20 dBm)

Introduction 1

Model

8485A

Option 8485A

-033

8481A

8482A

Frequency range

50 MHz to 26.5 GHz

26.5 MHz to 33 GHz

10 MHz to 18 GHz

100 kHz to

4.2 GHz

Maximum SWR

50 MHz to 100 MHz: 1.15

100 MHz to 2 GHz: 1.10

2 GHz to 12.4 GHz: 1.15

12.4 GHz to 18 GHz: 1.20

18 GHz to 26.5 GHz: 1.25

26.5 GHz to 33 GHz: 1.40

10 MHz to 30 MHz: 1.40

30 MHz to 50 MHz: 1.18

50 MHz to 2 GHz: 1.10

2 GHz to 12.4 GHz: 1.18

12.4 GHz to 18 GHz: 1.28

100 kHz to 300 kHz: 1.60

300 kHz to 1 MHz: 1.20

1 MHz to 2 GHz:

1.10 2 GHz to 4.2

GHz: 1.30

Power

[a]

linearity

+10 dBm to +20 dBm: ±3%

Maximum power

300 mW avg, 15 W pk

30 W.µs / pulse

300 mW avg, 15 W pk

30 W.µs / pulse

300 mW avg, 15 W pk

30 W.µs / pulse

300 mW avg, 15W pk

30 W.µs / pulse

Connector type Weight

Net: 0.2 kg

APC - 3.5mm(m)

Type-N(m)

(0.38 lb) Shipping:

0.5 kg (1.0 lb)

Net: 0.2 kg (0.38 lb)

Shipping: 0.5 kg (1.0 lb)

Net: 0.2 kg (0.38 lb)

Shipping: 0.5 kg (1.0 lb)

Net: 0.2 kg (0.38 lb)

Shipping: 0.5 kg (1.0 lb)

Keysight 8480 Series Operating and Service Manual 27

1Introduction

Tab le 1-7 100 mW sensors, 1 µW to 100 mW (–30 dBm to +20 dBm)

Model

8483A (75ohm)

8487A

[a] Negligible deviation except for those power ranges noted.

Frequency range

100 kHz to 2GHz

50 MHz to 50 GHz

Maximum SWR

100 kHz to 600 kHz: 1.80

600 kHz to 2 GHz: 1.18

50 MHz to 100 MHz: 1.15

100 MHz to 2 GHz: 1.10

2 GHz to

12.4 GHz: 1.15

12.4 GHz to 18 GHz: 1.20

18 GHz to

26.5 GHz: 1.25

26.5 GHz to 40 GHz: 1.30

40 GHz to 50 GHz: 1.50

Power

[a]

linearity

+10 dBm to +20 dBm: ±3%

Maximum power

300 mW avg, 10W pk

300 mW avg, 15W pk

30 W.µs / pulse

Connector type Weight

Net: 0.2 kg (0.38

Type-N(m) (75 ohm)

2.4 mm (m)

lb) Shipping: 0.5 kg

(1.0 lb)

Net: 0.14 kg (0.28 lb)

Shipping: 0.5 kg (1.0 lb)

28 Keysight 8480 Series Operating and Service Manual

Introduction 1

Table 1-8 High sensitivity sensors, 100 pW to 10 µW (–70 dBm to –20 dBm)

Model

8481D

8485D

Frequency range

Maximum SWR

Power linearity

[a]

power

Maximum

Connector type Weight

10 MHz to 30 MHz: 1.40

30 MHz to 4 GHz: 1.15

[b]

10 MHz to 18 GHz

4 GHz to 10 GHz: 1.20

-30 dBm to

-20 dBm: ±1%

100 mW avg, 100 mW pk

Type-N (m)

10 GHz to

Net: 0.16 kg (0.37 lb)

Shipping: 0.5 kg

(1.0 lb) 15 GHz: 1.30 15 GHz to 18 GHz: 1.35

50 MHz to 100 MHz: 1.19

100 MHz to 4 GHz: 1.15

[b]

50 MHz to 26.5 GHz

4 GHz to 12 GHz: 1.19

-30 dBm to

-20 dBm: ±2%

100 mW avg, 100 mW pk

APC - 3.5mm (m)

12 GHz to

Net: 0.2 kg (0.38

lb)

Shipping: 0.5 kg

(1.0 lb) 18 GHz: 1.25

18 GHz to

26.5 GHz: 1.29

Keysight 8480 Series Operating and Service Manual 29

1Introduction

Tab le 1-8 High sensitivity sensors, 100 pW to 10 µW (–70 dBm to –20 dBm)

Model

Option 8485D

-033

[b]

8487D

[a] Negligible deviation except for those power ranges noted.

[b] Includes 11708A 30 dB attenuator for calibrating against 0 dBm, 50 MHz power reference. The 11708A is factory set to 30 dB ±0.05 dB at

50 MHz, traceable to NIST. SWR < 1.05 at 50 MHz.

Frequency range

50 MHz to 33 GHz

50 MHz to 50 GHz

Maximum SWR

26.5 GHz to 33 GHz: 1.35

50 MHz to 100 MHz: 1.19

100 MHz to 2 GHz: 1.15

2 GHz to 12.4 GHz: 1.20

12.4 GHz to 18 GHz: 1.29

18 GHz to 34 GHz: 1.37

34 GHz to 40 GHz: 1.61

40 GHz to 50 GHz: 1.89

Power

[a]

linearity

-30 dBm to

-20 dBm: ±2%

-30 dBm to -20 dBm: ±2%

Maximum power

100 mW avg, 100 mW pk

10 W.µs / pulse

Connector type Weight

Net: 0.2 kg (0.38 APC - 3.5mm (m)

2.4 mm (m)

lb)

Shipping: 0.5 kg

(1.0 lb)

Net: 0.2 kg (0.38

lb)

Shipping: 0.5 kg

(1.0 lb)

Supplemental Characteristics

Supplemental characteristics are intended to provide additional information, useful in applying the power sensor by giving typical (expected) but not warranted performance parameters.

30 Keysight 8480 Series Operating and Service Manual

Figure 1-6 Typical CAL FACTOR and SWR vs. Frequency

Frequency (GHz)

Cal factor (%)

SWR

Introduction 1

Keysight 8480 Series Operating and Service Manual 31

1Introduction

Figure 1-7 Typical CAL FACTOR and SWR vs. Frequency (8485D)

32 Keysight 8480 Series Operating and Service Manual

Introduction 1

Figure 1-8 Typical CAL FACTOR and SWR vs. Frequency (8487D)

Keysight 8480 Series Operating and Service Manual 33

1Introduction

Installation

Initial Inspection

Inspect the shipping container. If the container or packing material is damaged, it should be kept until the contents of the shipment have been checked mechanically and electrically. If there is mechanical damage or if the instrument does not pass the performance tests, notify the nearest Keysight Technologies office. Keep the damaged shipping materials (if any) for inspection by the carrier and an Keysight Technologies representative.

Original Packaging

Containers and materials identical to those used in factory packaging are available through Keysight Technologies’ offices. If the instrument is being returned to Keysight Technologies for servicing, attach a tag indicating the type of service required, return address, model number, and serial number. Also, mark the container FRAGILE to assure careful handling. In any correspondence, refer to the instrument by model number and serial number.

Interconnections

Refer to the power meter’s User’s Guide for interconnecting instructions.

Storage and Shipment

Environment

The instrument should be stored in a clean, dry environment. The following limitations apply to both storage and shipment:

Temperature

Relative humidity <95%

Altitude < 7,600 metres (25,000 ft.)

34 Keysight 8480 Series Operating and Service Manual

- 40 to +75

Operation

WARNING

Environment

Operating Precautions

Introduction 1

The operating environment for the Power Sensor should be as follows:

Temperature

Relative humidity <95%

Altitude < 4,572 metres (15,000 ft.)

Before the Power Sensor is connected, the following precautions must be observed.

0 to +55

BEFORE CONNECTING THE POWER SENSOR TO ANOTHER INSTRUMENT, ensure that the instrument and power meter are connected to the protective (earth) ground.

Keysight 8480 Series Operating and Service Manual 35

Power Meter Calibrations

Power Meter to Power Sensor calibration procedures differ with the power meter. Follow the calibration procedure located in your power meter’s user’s guide.

Temperature Sensitivity

The sensitivity of the power sensor is influenced by ambient temperature. The sensor should be recalibrated at each change in temperature to obtain the most accurate results. Typical temperature sensitivity variations are shown in for the 8481D power sensor.

1Introduction

Temperature (oC)

Sensitivity

change (dB)

01020 3040 5060

-0.5

-1.0

Figure 1-9 Typical influence of temperature on sensitivity

Operating Instructions

To operate the Power Sensor, refer to the operating instructions in of the power meter’s user’s guide.

Power Measurements

To correct for varying responses at different frequencies a cal factor table is included on the Power Sensors. To use the cal factor at the frequency of interest, adjust the power meter’s CAL FACTOR control according to the instructions in the power meter’s user’s guide.

If you are using an Keysight 435B or Keysight 436A, the minimum cal factor setting is 85% and the maximum is 100%. If the cal factor setting for your frequency of interest is below the meter’s minimum or above the meter’s maximum, set the cal factor control to 100%, and divide the reading, in watts unit, by the decimal equivalent of the cal factor. For example, if the cal factor is 75%, divide the reading by 0.75. (This will result in a larger value of power than that displayed by the meter) If the cal factor is 104% divide the reading by 1.04. (This will result in a smaller value of power than that displayed by the meter).

If reading in dBm, use the chart in Table 1-9 to convert the cal factor to dB and

36 Keysight 8480 Series Operating and Service Manual

add this value to the reading. Interpolate for values between those shown. Set the cal factor control to 100%. If the cal factor is 75%, add 1.25 dB to the displayed

Introduction 1

value. On the other hand, if the cal factor is 104%, subtract 0.170 from the displayed reading.

Table 1-9 Cal factor to dB conversion chart

Cal factor dB Cal factor dB

70% 1.55 101% –0.43

71% 1.49 102% –0.86

72% 1.43 103% –0.128

73% 1.37 104% –0.170

74% 1.31 105% –0.212

75% 1.25 106% –0.253

76% 1.19 107% –0.294

77% 1.14 108% –0.334

78% 1.08 109% –0.374

79% 1.02 110% –0.414

80% 0.97

81% 0.92

82% 0.86

83% 0.81

84% 0.76

85% 0.71

Keysight 8480 Series Operating and Service Manual 37

1Introduction

Modulation Effects

When measuring RF or microwave sources that are modulated at the chopper frequency (nominally 220 Hz), at the first or second harmonic or submultiples of the chopper frequency, beat notes may occur. Unless these beat notes are exactly the chopper frequency, they can usually be eliminated by averaging (filtering) since the amplitudes are plus and minus the actual power. These frequencies may also be avoided by changing the modulation frequency slightly, if possible.

Refer to the power meter’s user’s guide for information on setting the averaging (filtering).

38 Keysight 8480 Series Operating and Service Manual

Keysight 8480 Series Coaxial Power Sensors Operating and Service Manual

2 General Information

Connector Care 40 Performance Test 41 Adjustments 50 Replaceable Parts 51

This chapter contains information about recommended equipment, performance tests, and replacement parts of the Keysight Coaxial Power Sensors.

2 General Information

CAUTION

Connector Care

Keeping in mind its flammable nature, a solution of pure isopropyl or ethyl alcohol can be used to clean connectors.

The RF connector bead deteriorates when contacted by any chlorinated or aromatic hydrocarbon such as acetone, trichlorethane, carbon tetrachloride, and benzene.

Do not attempt to clean connectors with anything metallic such as pins or paper clips.

Clean the connector face by first using a blast of compressed air. If the compressed air fails to remove contaminants use a cotton swab dipped in isopropyl or ethyl alcohol. If the swab is too big, use a round wooden toothpick wrapped in a lint free cloth dipped in isopropyl or ethyl alcohol.

Torque

For operation to 18 GHz, the newer 8480 series power sensors have a Type-N hex nut for tightening to the device-under-test or the power meter's 1 mW Power Reference. Older 8480 series power sensors have a knurled portion on the connector. Turn the connector nut (or knurled portion) only to tighten, the torque should not exceed 135 N-cm (12 in-lb) to avoid damage to the connector.

For APC3.5 mm and 2.4mm connectors the torque should not exceed 90 N-cm (8 in-lb) to avoid damage to the connector.

Damage can occur if torque is applied to the power sensor body.

40 Keysight 8480 Series Operating and Service Manual

Performance Test

NOTE

Voltage standing wave ratio (VSWR) and reflection coefficient (Rho) performance verification test

VSWR is a measure of how efficiently radio frequency (RF) power is transmitted from an RF power source. In real systems, mismatched impedances between the RF source and load can cause some of the power to be reflected towards the source and vary the VSWR. The Maximum SWR values (also expressed in terms of the reflection coefficient [Rho]) for each model of power sensors are listed in

Table 2-1.

For overlapping frequency points, refer to the lower SWR specification.

This performance verification requires the following equipment:

– PNA Series network analyzer (8753ES and/or 8510C)

– calibration kit (85036B and/or 85052B)

General Information 2

Procedure

1 Turn on the network analyzer and allow it to warm up for approximately an

hour.

2 Set the start and stop frequency of the network analyzer according the power

sensor frequency operating range.

3 Calibrate the network analyzer using the appropriate calibration kit. Perform

calibration for the open, short, and load circuits of the network analyzer.

4 After calibration, connect the power sensor to the test port of the network

analyzer. Set the format for data trace to SWR.

5 Compare the measured results to the maximum SWR (reflection coefficient) in

Table 2-1 . If the verification fails, refer to “Ad justments” on page 50.

Keysight 8480 Series Operating and Service Manual 41

2 General Information

Tab le 2-1 Power sensor SWR and reflection coefficient

Frequency Maximum SWR (reflection coefficient) Actual measurement

8481A

10 to 30 MHz < 1.40 (0.166)

30 to 50 MHz < 1.18 (0.083)

50 MHz to 2 GHz < 1.10 (0.048)

2 to 12.4 GHz < 1.18 (0.083)

12.4 to 18 GHz < 1.28 (0.123)

8482A

100 to 300 kHz < 1.60 (0.231)

300 kHz to 1 MHz < 1.20 (0.091)

1 MHz to 2 GHz < 1.10 (0.048)

2 to 4.2 GHz < 1.30 (0.130)

8483A

100 to 600 kHz < 1.80 (0.286)

600 kHz to 2 GHz < 1.18 (0.083)

8485A

50 to 100 MHz < 1.15 (0.070)

0.1 to 2 GHz < 1.10 (0.048)

2 to 12.4 GHz < 1.15 (0.070)

12.4 to 18 GHz < 1.20 (0.091)

18 to 26.5 GHz < 1.25 (0.111)

26.5 to 33 GHz < 1.40 (0.166)

8487A

50 to 100 MHz < 1.15 (0.070)

0.1 to 2 GHz < 1.10 (0.048)

2 to 12.4 GHz < 1.15 (0.070)

42 Keysight 8480 Series Operating and Service Manual

General Information 2

Table 2-1 Power sensor SWR and reflection coefficient

Frequency Maximum SWR (reflection coefficient) Actual measurement

12.4 to 18 GHz < 1.20 (0.091)

18 to 26.5 GHz < 1.25 (0.111)

26.5 to 40 GHz < 1.30 (0.130)

40 to 50 GHz < 1.50 (0.20)

8481B

10 MHz to 2 GHz < 1.10 (0.048)

2 to 12.4 GHz < 1.18 (0.083)

12.4 to 18 GHz < 1.28 (0.123)

8482B

100 kHz to 2 GHz < 1.10 (0.048)

2 to 4.2 GHz < 1.18 (0.083)

8481H

10 MHz to 8 GHz < 1.20 (0.091)

8 to 12.4 GHz < 1.25 (0.112)

12.4 to 18 GHz < 1.30 (0.130)

8482H

100 kHz to 4.2 GHz < 1.20 (0.091)

8481D

10 to 30 MHz < 1.40 (0.167)

0.03 to 4 GHz < 1.15 (0.070)

4 to 10 GHz < 1.20 (0.091)

10 to 15 GHz < 1.30 (0.130)

15 to 18 GHz < 1.35 (0.112)

8485D

50 to 100 MHz < 1.19 (0.085)

0.1 to 4 GHz < 1.15 (0.070)

Keysight 8480 Series Operating and Service Manual 43

2 General Information

Tab le 2-1 Power sensor SWR and reflection coefficient

Frequency Maximum SWR (reflection coefficient) Actual measurement

4 to 12 GHz < 1.19 (0.085)

12 to 18 GHz < 1.25 (0.112)

18 to 26.5 GHz < 1.29 (0.127)

8487D

50 to 100 MHz < 1.19 (0.085)

0.1 to 2 GHz < 1.15 (0.069)

2 to 12.4 GHz < 1.20 (0.091)

12.4 to 18 GHz < 1.29 (0.127)

18 to 34 GHz < 1.37 (0.156)

34 to 40 GHz < 1.61 (0.234)

40 to 45 GHz < 1.86 (0.301)

45 to 50 GHz < 1.89 (0.310)

Zero set performance verification

This performance verification is carried out to verify that a minimal amount of residual offset error is present after zeroing has been performed. The offset error is caused by contamination from several sources including the noise of the device-under-test (DUT) itself. Zero set is the difference between the power levels indicated by the DUT, after executing zeroing and the true zero power. Ideally, this difference should be zero.

This performance test requires a compatible Keysight power meter with the DUT and a computer with the Keysight IO Libraries Suite installed.

System specification: ±50 nW (for all 848xA) and

±20 pW (for all 848xD), tested at 50 MHz

Recommended power meter: EPM series power meters (E4418B and E4419B),

the EPM-P series power meters (E4416A and E4417A)

44 Keysight 8480 Series Operating and Service Manual

General Information 2

DUT

Power

meter

Power ref

Power sensor

Power meter

Power sensor cable

Channel A

Recommended 50 MHz, 50 Ohm Type-N (f) to 75 Ohm Type-N (m):

Recommended 50 MHz, 30 dB Attenuator Pad APC-3.5mm to Type-N:

11852B adapter (used with 8483A)

11708A adapter (used with 8481/5/7D)

Procedure

Figure 2-1 Zero set performance verification equipment setup

1 Connect the DUT (8483A/1D/5D/7D) to the power meter as shown in the

following figure.

Figure 2-2 DUT to power meter connection

Keysight 8480 Series Operating and Service Manual 45

2 Warm up the DUT for approximately 30 minutes.

2 General Information

3 Launch the Interactive IO on the Keysight IO Libraries Suite to send SCPI

commands to the DUT.

4 Reset the power meter in a known state by sending “*RST” command,

followed by “SYST:PRES” command to pre-set the meter's output to its default value.

5 Connect the DUT to the power meter 1 mW calibrator and perform zeroing for

the DUT by sending “CAL:ZERO:AUTO ONCE”.(Please use the recommended adapter for the respective model)

6 Perform calibration for the DUT by sending “CAL:AUTO ONCE”.

7 Set the frequency of the DUT to 50 MHz by sending “FREQ 50MHz”.

8 Enable auto-averaging for the DUT by sending “AVER:COUN:AUTO ON".

9 Change the power measurement unit of the DUT to watt by sending

“UNIT:POW W”.

10 Disconnect the DUT from the power meter 1 mW calibrator.

11 Perform zeroing for the DUT by sending “CAL:ZERO:AUTO ONCE”.

12 Set the DUT to the single trigger mode by sending “INIT:CONT OFF”.

13 Read the noise level of the DUT by sending “READ” and then record the

reading.

14 Repeat step 13 for 10 times and then calculate the mean value of the readings.

15 Compare the calculated mean value to the system specification. If the test

fails, refer to “Adjustments” on page 50.

Power linearity performance verification

The power linearity performance verification measures the relative linearity error of the 8480. All measurements are performed at 50 MHz. The reference power level for the linearity measurement is 0 dBm for the 8483A and -30 dBm for 8481/5/7D.

This performance verification requires the following equipment:

– signal generator (N5182A)

– thermocouple-based average power sensor, as a reference sensor

(N8481A/5A/7A)

– power meter (E4416/7A)

46 Keysight 8480 Series Operating and Service Manual

General Information 2

Signal generator

Amplifier

10 dB step attenuator

1 dB step attenuator

Attenuator/ switch driver

(Optional)

DUT

Power meter

Reference sensor

Power splitter

– power splitter (11667A-Option 001)

–amplifier

– step attenuators (8494H and 8496H)

– attenuator/switch driver (11713B)

– 50 MHz, 30 dBm attenuator pad (11708A)

Procedure

1 Turn on the signal generator and power meter. Connect the DUT (848xA) to

the channel A and the reference sensor (N8481A) to the channel B of the power meter (E4416/7A). Allow them to warm up for approximately an hour.

2 Zero and calibrate the DUT using the reference sensor with the power meter.

For 8481/5/7D models, during the zero and calibration please use the 50 MHz, 30 dBm attenuator pad (11708A).

3 Connect the power splitter (11667A option 001) to the RF output of the signal

generator (N5182A). The equipment setup is as shown in the following figure.

Keysight 8480 Series Operating and Service Manual 47

Figure 2-3 Power linearity performance verification equipment setup

4 Set the continuous wave signal frequency of the signal generator, DUT, and

reference sensor to 50 MHz. Set DUT to AVERAGE ONLY mode.

2 General Information

CAUTION

DUT/ref

()Measured power at 0 dBm P

DUT/ref at 0 dBm

()–=

Linearity error (dB) P

DUT

[]

norm to 0 dBm

ref

[]

norm to 0 dBm

–=

Linearity error (%) Anti

DUT

[]

norm to 0 dBm

ref

[]

norm to 0 dBm

–

-------------------------------------------------------------------------------------------







log 1– 100

×=

5 Start tuning the signal generator and/or attenuator/switch driver (optional)

until the DUT measures the power level as close as 0 dBm. Record the values as P

Do not exceed the maximum input power (27 dBm) of the power splitter to avoid damage to the power splitter.

at 0 dBm and P

DUT

at 0 dBm.

ref

6 Record the power measured by the power meter for DUT as P

DUT

and

reference power sensor as Pref.

7 Normalize both P

and P

ref

to the power measured at 0 dBm, using the

DUT

following equation:

8 Calculate the linearity error of the DUT for the power level using the following

equations:

9 Compare and record the calculated linearity error against the system linearity

error specifications.

10 Repeat step 6 to step 9 by sweeping through the warranted power levels for

power linearity test as listed in the data sheet at 50 MHz.

11 Repeat step 5 to step 11 for normal mode. If the verification fails, refer to

“Adjustments” on page 50.

48 Keysight 8480 Series Operating and Service Manual

General Information 2

System linearity error specification DUT error2Ref sensor error

+±=

System linearity error specification (3%)2(0.8%)

+± 3.10%±==

12 The linearity system specification is calculated using the root sum of the

squares (RSS) method by considering the error caused from the reference sensor used and the DUT error in the system at 50 MHz. The error specification caused by the reference sensor and the DUT can be found in their respective data sheet. The RSS error specification calculation is computed by using the following equation:

The following example of the DUT is measured at 50Mhz, 20dBm:

– DUT used is 8481A

– Reference sensor used is N8481A

Keysight 8480 Series Operating and Service Manual 49

2 General Information

Adjustments

Adjustments are usually required on a yearly basis. They are normally performed only after a performance verification has indicated that some parameters are out of specification. Performance verification must be completed after any repairs that may have altered the characteristics of the 8480 Series power sensors.

The 8480 Series power sensors can be adjusted using the Keysight N7800 Series calibration software or can be returned to Keysight for adjustments. To arrange the return, contact the Keysight Service Center.

50 Keysight 8480 Series Operating and Service Manual

Replaceable Parts

Table 2-2 to Table 2-7 are a list of replaceable parts. Figure 2-4 illustrates the

major parts. To order a part listed in Tab le 2-2 to Table 2-7, contact your nearest Keysight Technologies Sales and Service Office.

General Information 2

Figure 2-4 Illustrated major parts breakdown

Keysight 8480 Series Operating and Service Manual 51

2 General Information

Tab le 2-2 Bulkhead assembly

Model

8481A A1 08481-60004 1 Bulkhead Assembly, Type N

8481A Opt 001 A1 08481-60005 1 Bulkhead Assembly, Type APC-7

8482A A1 08482-60003 1 Bulkhead Assembly, Type N

8483A A1 08483-60003 1 Bulkhead Assembly, Type N

8485A A1 08485-60007 1 Bulkhead Assembly, 3.5mm

8485A Opt 033 A1 08485-60011 1 Bulkhead Assembly, 3.5mm

8487A A1 08487-60002 1 Bulkhead Assembly, 2.4mm

8481B A1 08481-60019 1 Bulkhead Assembly, Type N

8482B A1 08482-60011 1 Bulkhead Assembly, Type N

8481D A1 08481-60145 1 Bulkhead Assembly, Type N

8485D A1 08485-60008 1 Bulkhead Assembly, 3.5mm

8485D Opt 033 A1 08485-60012 1 Bulkhead Assembly, 3.5mm

8487D A1 08487-67002 1 Bulkhead Assembly, 2.4mm

8481H A1 08481-60014 1 20dB Bulkhead Assembly, Type N

8482H A1 08482-60009 1 20dB Bulkhead Assembly, Type N

Reference designator

Part number Quantity Description

Tab le 2-3 Power sensor board assemblies

Model

848xA A2 5061-0982 1 Power Sensor Board Assembly

8481B/8482B A2 08481-60039 1 Power Sensor Board Assembly

8481D/8485D/8487D A2 5061-0983 1 Power Sensor Board Assembly

8481H/8482H A2 08481-60040 1 Power Sensor Board Assembly

Reference designator

Part number Quantity Description

52 Keysight 8480 Series Operating and Service Manual

General Information 2

Table 2-4 Common chassis components

Reference designator Part number Quantity Description

MP1-MP2 5040-6998 2 Plastic Shell

MP3-MP4 08481-20011 2 Chassis

MP6 1460-1978 1 Compression Spring

MP8-MP9 08481-00002 2 Shield

MP10-MP22 0515-0879 13 Screw

MP23 3030-0436 1 Screw

MP24 5040-6939 1 Clamp

MP25 5040-6940 1 Block

Table 2-5 Adapters and attenuators

Model Part number Quantity Description

8483A 1250-0597 1 50 Ohm to 75 Ohm Coax Adapter

8485A/8485D 08485-60005 1 3.5mm to N(m) Coax Adapter

8487A/8487D 08487-60001 1 2.4mm to N(m) Coax Adapter

8481B 08498-60001 1 Coaxial Fixed 30dB Attenuator

8482B 08498-60010 1 Coaxial Fixed 30dB Attenuator

8481D/8485D/8487D 11708-60001 1 Precision 30dB Attenuator

Table 2-6 Identification labels

Model Part number Quantity Description

8481A 08481-80002 1 8481A ID Label

8482A 08482-80002 1 8482A ID Label

8483A 08483-80001 1 8483A ID Label

8485A 08485-80002 1 8485A ID Label

Keysight 8480 Series Operating and Service Manual 53

2 General Information

Tab le 2-6 Identification labels

Model Part number Quantity Description

8487A 08487-80001 1 8487A ID Label

8481B 08481-80004 1 8481B ID Label

8482B 08482-80003 1 8482B ID Label

8481D 08481-80011 1 8481D ID Label

8485D 08485-80003 1 8485D ID Label

8487D 08487-80004 1 8487D ID Label

8481H 08481-80003 1 8481H ID Label

8482H 08482-80001 1 8482H ID Label

Tab le 2-7 Miscellaneous labels

Part number Quantity Description

08481-80115 1 Cal Label (Blank) - For Zebra brand printers

08486-80006 1 Cal Label (Blank) - For impact printers

08481-80005 1 Mylar Overlay - For use with Cal Label 08486-80006

08486-80005 1 Side Label - Keysight Branding

7121-2422 1 Side Label - Caution (For all models except 8487A/8487D)

08487-80002 1 Side Label - Caution (For 8487A/8487D)

00346-80011 1 Information Label (For 8481D/8485D/8487D)

54 Keysight 8480 Series Operating and Service Manual

Keysight 8480 Series Coaxial Power Sensors Operating and Service Manual

3 Service

Principles of Operation 56 Troubleshooting 59 Repair 63 FET Balance Adjustment 65 Disassembly / Reassembly Procedures 69

This Service chapter contains information about principles of operation, troubleshooting, and repair of the Keysight Coaxial Power Sensors.

3Service

Principles of Operation

Thermocouple sensors

The A1 Bulkhead Assembly presents a 50 Ohm load (75 Ohm for model 8483A) to the RF source.

The RF signal is coupled through a dc blocking capacitor and absorbed by the thermocouples, generating a dc voltage proportional to the RF input power. The dc voltage is routed from the thermocouples to the input amplifier via gold wires reducing unwanted thermocouple effects. The gold wires, located in the black plastic block, pass through ferrite beads A2E1 and A2E2. The ferrite beads increase the self-inductance of the gold wires creating an RF choke. The result is to minimize RF feedthrough to the A2 Power Sensor Board Assembly.

The dc output from the bulkhead assembly is applied to the two field effect transistors (FETs) in A2U1. These transistors function as a sampling gate or chopper. The sampling rate is controlled by a 220 Hz square wave supplied by the power meter. The amplitude of the sampling gate output (at pin 3 of A2U1) is a 220 Hz square wave proportional to the power input. The sampled 220 Hz ac output is applied to the input amplifier A2Q1, which is the input stage for an operational amplifier

The Auto Zero Feedback circuit is coupled to the power sensor from the power meter. The dc voltage used to set the zero level is applied to the input of FET A2U1 by using A2R1 and A1TC1 as a voltage divider.

When the Power Sensor is used with a Power Meter, the resistance to ground from J1-K (Mount Resistor) allows the Power Meter to determine the sensor's dynamic range.

56 Keysight 8480 Series Operating and Service Manual

Diode sensors

The A1 Bulkhead Assembly presents a 50 Ohm load to the RF source.

A diode assembly in the bulkhead rectifies the applied RF to produce a dc voltage that varies with the square of the RF power across the 50 Ohm load. Thus the voltage varies with the RF power dissipated in the load.

This low level DC voltage is passed on gold wires through ferrite beads A2E1 and A2E2. The ferrite beads increase the self-inductance of the gold wires causing this portion of the wires to provide the properties of an RF choke. The result is to minimize RF feedthrough to the A2 Power Sensor Board Assembly.

The A2 Power Sensor Board Assembly also contains various components that comprise a shaping network. This network brings about a linear change in the amplitude of the square wave output as RF input power changes. A shaping network is necessary in diode power sensors to compensate for the characteristics of the thermocouple type shaping in the power meter, and to make minor diode corrections. In order to bring about a linear change in amplitude, the components in this network are factory selected to match variations of the diode assembly in the bulkhead.

Service 3

When the Power Sensor is used with a Power Meter, the resistance to ground from J1-K (Mount Resistor) allows the Power Meter to determine the sensor's dynamic range.

Keysight 8480 Series Operating and Service Manual 57

3Service

Figure 3-1 Schematic diagram

58 Keysight 8480 Series Operating and Service Manual

Troubleshooting

NOTE

CAUTION

Troubleshooting information is intended to first isolate the Power Sensor or the Power Meter as the defective component. When the Power Sensor is isolated, troubleshooting information is intended to identify the A1 Bulkhead Assembly or the A2 Power Sensor Board Assembly as the defective component.

Before you open the Power Sensor to continue with the troubleshooting procedures, try the substitution method of elimination. Use another power meter, known to be in good operating condition, with the suspected power sensor and cable. If the same problem occurs with the “known good” power meter, substitute a “known good” power sensor cable.

Troubleshooting should be performed with the Power Sensor opened, and the printed circuit board exposed. Refer to the “Disassembly / Reassembly Procedures” on page 69.

When a failed assembly has been identified, refer to the repair section in either the “A1 Bulkhead Assembly” on page 63 or the “A2 Power Sensor Board Assembly” on page 64.

The FETs in A2U1 are light sensitive, and dc levels are shifted slightly when the FETs are exposed.

Service 3

Excessive power damages the power sensor.

Electrostatic discharge renders the power sensor inoperative. Troubleshooting and Repair procedures must be carried out at a static free workstation.

Troubleshooting - eliminating the power meter and sensor cable

Where a “known good” power meter and/or sensor cable is unavailable, another means must be used to isolate the fault to the power sensor.

Keysight 8480 Series Operating and Service Manual 59

3Service

CAUTION

Troubleshooting - power sensors

A1 Bulkhead (thermocouple sensors)

This is done by ensuring the power meter is providing the correct 220Hz drive signal. Check the following levels of the square wave with an oscilloscope.

– At the black/white wire: -0.05 ± 0.05 Vdc (top of square wave).

– At the brown/white wire: -9Vdc (bottom of square wave).

If the levels are incorrect, then the power meter or sensor cable is at fault. Refer to the power meter service manual for troubleshooting information.

If the levels are correct then the Power Sensor is at fault. Continue by troubleshooting the A1 Bulkhead Assembly.

The most common cause of Power Sensor failure is the application of power levels beyond the specified tolerance. The second most common cause of failure is applying torque to the body of the Power Sensor. Either of these common causes damages the bulkhead cartridge unit (which holds the thermocouples/diodes). If this happens, the fault causes a short or an open between the two gold wires.

Disconnect the gold wires from the A2 assembly before measuring the resistance. Be extremely careful when measuring across the gold wires. They are delicate and can be damaged easily.

1 Disconnect all cables from the power sensor.

2 Remove the clamp holding the two gold wires.

3 Resistance measured between the two gold wires from the A1 Bulkhead

Assembly is listed in Figure 3-1.

60 Keysight 8480 Series Operating and Service Manual

Service 3

CAUTION

NOTE

Table 3-1 Bulkhead assembly resistance

Model Measured resistance

8481A, 8481B, 8481H, 8485A, 8487A: 200 Ohms ± 10 Ohms

8482A, 8482B, 8482H: 245 Ohms ± 12.5 Ohms

8483A: 375 Ohms ± 17.5 Ohms

If the resistance value is incorrect (failure is usually indicated by an open circuit), then the A1 Bulkhead Assembly is defective. If the resistance is correct then continue to test the A2 Power Sensor Board Assembly.

A1 Bulkhead (diode sensors)

Disconnect the gold wires from the A2 assembly before measuring the voltage. Be extremely careful when measuring across the gold wires. They are delicate and can be damaged easily.

1 Disconnect all cables from the Power Sensor.

2 Remove the clamp holding the two gold wires.

3 Connect the Precision 30dB Attenuator to the 1mW Power Reference

connector on the power meter.

4 Connect the Power Sensor to the Precision 30dB Attenuator.

Models 8485A and 8487A require 3.5mm and 2.4mm adapters respectively.

5 Turn on the 1mW Power Reference, and measure the voltage across the two

gold wires. The voltage should be between 0.9mV and 1.5mV. If the voltage is incorrect, then the A1 Bulkhead Assembly is defective. If the voltage is correct then continue to test the A2 Power Sensor Board Assembly.

Keysight 8480 Series Operating and Service Manual 61

3Service

A2 Power Sensor Board Assembly

It is extremely rare for the A2 Assembly to fail. Eliminate the power meter, the sensor cable, and the A1 Bulkhead Assembly before suspecting the A2 Assembly.

In most cases, the operational amplifier (made up of A2Q1 and the first amplifier of the power meter,) is operating correctly if the dc voltage on the metal cover of A2Q1 (collector) is -70 ±30 mV dc.

62 Keysight 8480 Series Operating and Service Manual

Repair

NOTE

Service 3

Power Sensor repair consists of replacing either the A1 Bulkhead Assembly, or the A2 Power Sensor Board Assembly.

A1 Bulkhead Assembly

Repair Strategy

The recommended repair strategy for the A1 Bulkhead Assembly is to completely replace it. The replacement Bulkhead is calibrated at the factory, and is supplied with a calibration report and a new calibration sticker for the Power Sensor.

Procedure

1 Order your new or restored A1 Bulkhead Assembly from Tab le 2- 2.

2 Follow the disassembly and reassembly procedures for Bulkhead removal and

replacement. See “Disassembly / Reassembly Procedures” on page 69.

3 Check the FET balance using the procedure described in “FET Balance

Adjustment” on page 65. If you did not disturb the wires, it is likely that no adjustment is necessary.

4 Place the new calibration sticker on the plastic shell of the power sensor.

Although the recommended Bulkhead strategy is to completely replace it, we are aware that some customers have both the ability and experience that enables them to disassemble and repair Bulkheads to a lower level. For this reason, Appendix B provides exploded views of the various Bulkheads, and tables listing the parts.

Lower level Bulkhead repair can be more economical than replacement, although this may be offset by the need to invest in sensor calibration equipment and a SWR test set-up.

Keysight 8480 Series Operating and Service Manual 63

3Service

A2 Power Sensor Board Assembly

Repair Strategy

The recommended repair strategy for the A2 Power Sensor Board Assembly is to completely replace it. Replacing this assembly is usually less costly than the time it takes to troubleshoot and replace faulty components.

Procedure

When replacing the A2 Power Sensor Board Assembly, some soldering is required in order to remove and replace the wires from connector J1. Remember that the Power Sensor is a highly sensitive device. As such, it is affected by very small temperature differences between its components. After performing any soldering in the unit, wait several hours for the unit to reach thermal equilibrium before using or testing it.

1 Use a temperature controlled 600F (311C) with a zero crossover tip.

2 Use a low temperature RMA flux SN 62 solder.

3 Do not attempt to remove flux residue from around solder joints. Using a

cleaning solution may spread the flux over the entire assembly in a thin sticky layer.

64 Keysight 8480 Series Operating and Service Manual

FET Balance Adjustment

NOTE

The FET balance adjustment should be performed if the wires connecting J1 (the sensor cable connector) to A2 (the power sensor board assembly) have been moved. If you have replaced A2 assembly or moved the wires during troubleshooting you need to perform this adjustment.

You do not need to perform a FET balance adjustment after an A1 bulkhead assembly replacement, if the wires between J1 and A2 have not been disturbed.

Equipment Required

–Oscilloscope

– BNC cables (2 required)

– Power meter (modified as described in Appendix A)

Test Description

Service 3

This test applies to both thermocouple and diode power sensors. Among the required equipment is a modified E4418B Power Meter. The High Gain output of the power meter is connected to Channel 1 of an oscilloscope, and the Chop Output (220Hz square wave) of the power meter is connected to the oscilloscope trigger - the High Gain output is the amplified version of the Power Sensor chopped signal. Ideally, when no RF power is applied to the power sensor, the High Gain output signal displayed on the oscilloscope is a straight line. If there is a sensor offset, the offset signal is visible on the oscilloscope as a square wave (chopped signal). Also, a switching transient (spike) usually occurs at the edge of the chopped signal, due to the switching of the FET in the Power Sensor. Sensor offset and spike balance are affected by the relative positions of the wires connected to pins G and H of connector J1. One wire is black and white; the other is brown and white. Moving the black and white wire adjusts the amplitude of the switching transient (spike). Moving the brown and white wire changes the offset. Once positioned, care must be taken not to displace these wires. To correctly position these wires, perform the “FET Balance Procedure” on page 66.

Keysight 8480 Series Operating and Service Manual 65

3Service

FET Balance Procedure

1 Set the power meter as follows:

CAL FACTOR 100%

POWER REF ON

2 Connect the HIGH GAIN OUTPUT on the modified Power Meter to CHANNEL 1

on the Oscilloscope and set it up as follows:

POSITION 0 Volts (centered)

COUPLING AC

PROBE 1:1

DISPLAY AVERAGE

AVERAGE 8

VECTORS ON

GRID ON

MAIN/DELAYED MAIN

TIME REF CENTER

TIME/DIV 500 μs

VOLTS/DIV 50 mV

3 Connect the CHOP OUTPUT on the modified Power Meter to CHANNEL 2 on

the Oscilloscope and set it up as follows:

MODE AUTO LEVEL

TRIGGER SOURCE CHANNEL 2

VOLTS/DIV 5 V

POSITION -5 V

66 Keysight 8480 Series Operating and Service Manual

Service 3

NOTE

4 Connect the Power Sensor to channel A of the Power Meter.

Heat can affect the adjustments so handle the sensor as little as possible.

5 Adjust the black/white and brown/white wires until the waveform shown on

the oscilloscope is similar to that shown in Figure 3-2. This shows an example of a High Gain output signal with acceptable sensor offset and spike balance settings.

Figure 3-2 Example of an acceptable waveform

6 Allow no more than 50 mV variance on the sensor offset step (i.e. from

top-to-top or bottom-to-bottom of the waveform). Figure 3-3 shows an example of a High Gain output signal with an unacceptably high sensor offset setting.

Keysight 8480 Series Operating and Service Manual 67

3Service

NOTE

Figure 3-3 Example of an unacceptable waveform

You will find that positioning the wire for switching transients affects the offset. Go back and forth between the two wires, positioning and repositioning, until both adjustments are deemed acceptable.

7 Reassemble the Power Sensor, ensuring that the waveform shown on the

oscilloscope does not change. If the waveform has changed, remove the cover and readjust the black/white and brown/white wires again.

68 Keysight 8480 Series Operating and Service Manual

Disassembly / Reassembly Procedures

CAUTION

NOTE

Disassembly Procedure

Disassemble the Power Sensor by performing the following steps:

Disassembly must be performed in sequence described in the following procedure, otherwise damage may be caused to the two gold wires between the bulkhead assembly and the Power Sensor Board Assembly. If these wires are damaged, the A1 Bulkhead Assembly must be replaced.

Every power sensor has an individually prepared label on the housing. If more than one power sensor is disassembled at a time, be sure to mate the correct power sensor and housing when reassembling.

1 Insert the blade of a large screwdriver between the two-piece plastic shell at

the rear of the Power Sensor. Gently pry the sections apart. (See .)

Service 3

Keysight 8480 Series Operating and Service Manual 69

3Service

Figure 3-4 Removing the power sensor’s cover

2 At the other side of the sensor, again pry the cover shell sections apart.

Remove the shells and the inner magnetic shields.

3 Position the Power Sensor as shown in (top). The small hole 5 should be on

the left side of the RF input connector. Remove the allen cap screws 1, 2, 10, and 13. Loosen 11 and 12. Remove the upper chassis from the Power Sensor.

4 Remove the spring clamp cap screw 7 to free the gold leads which come from

the Bulkhead Assembly.

5 Remove cap screws 3, 4, and 5.

6 Slide the Bulkhead Assembly straight out from the chassis.

7 Remove cap screws 8, 9, 11, 12, 14, and 15.

8 Lift the A2 Input Amplifier and J1 connector out of the chassis.

70 Keysight 8480 Series Operating and Service Manual

Service 3

CAUTION

Figure 3-5 Power sensor hardware locations

Reassembly Procedures

The gold wires connecting the A1 Bulkhead assembly and the A2 power sensor board assembly are extremely delicate and may be easily broken. Be careful when working around them.

Keysight 8480 Series Operating and Service Manual 71

3Service

CAUTION

1 Set the printed circuit board and connector into place as shown in , bottom

view.

2 Insert cap screws 8, 9, 11, 12, 14, and 15 but do not tighten.

3 Center the circuit board so there is equal air gap between each side and the

chassis. Tighten 8, 9, 14, and 15.

4 Insert screw 3, 4, and 5. Tighten only screw 5.

5 With small hole 5 to the left, carefully insert the gold leads on A1 bulkhead

assembly through the holes in the black plastic guide on A2 input amplifier.

6 Using tweezers, position the ends of the gold wires over the electrical pads.

DO NOT tighten clamp screw 6 excessively or the FET circuit may be broken.

7 Place and hold plastic clamp 16 over the gold wires. As you tighten the clamp

screw, watch the compression spring. Tighten the clamp screw 7 only until the spring coils touch. Any further tightening could damage the FET circuit.

8 Place the upper chassis in position and insert cap screws 1, 2, 10, and 13.

9 Tighten 1, 2, 3, and 4.

10 Tighten 10, 11, 12, and 13.

11 Place the plastic shells, magnetic shields, and the chassis together as shown

in Figure 2-4. Snap the plastic shells together.

72 Keysight 8480 Series Operating and Service Manual

Keysight 8480 Series Coaxial Power Sensors Operating and Service Manual

A EPM Series Power Meter

(E4418B) Modification

The Material and Tools Required 74 Modification Procedure 75

This Appendix describes the modification procedure for adapting an E4418B Power Meter to allow it to be used for the 8480 Series Power Sensor FET Balance Adjustment.

A EPM Series Power Meter (E4418B) Modification

NOTE

The Material and Tools Required

The following material and tools are required for this modification:

– A T-15 torque screwdriver.

–A Razor blade or Craft Knife.

– Three 30 cm lengths of AWG 20 single core wire.

– Three screw-fit BNC Female connectors

(Keysight Part Number 1250-0118).

– A fine tip marker pen and adhesive labels.

– A 10-20 Watt pencil tip soldering iron.

– 60/40 0.8 mm rosin activated core solder wire.

– A Wire stripper.

– 25 lb/in Torque Wrench - Size 7/16 in. AF.

Impact on Warranty

Please be aware that doing this modification requires you to open the power sensor. Therefore, as stated earlier, any attempt to disassemble the power sensor will void the warranty.

74 Keysight 8480 Series Operating and Service Manual

Modification Procedure

CAUTION

Remove these 2 screws

Precautions must be taken to protect the Power Meter’s PCBs from Electrical Static Damage (ESD).

1 Using the T-15 torque screwdriver, remove the two screws shown in

Figure A-1.

EPM Series Power Meter (E4418B) Modification A

Figure A-1 Remove screws

2 Remove the power meter handle. To remove the handle, pull the 2 ends as

shown in Figure A-2.

Keysight 8480 Series Operating and Service Manual 75

A EPM Series Power Meter (E4418B) Modification

PullPull

Slide cover this direction

Figure A-2 Remove the power meter handle

3 Remove the power meter cover. To remove the cover, slide it open as shown in

Figure A-3.

Figure A-3 Remove the power meter cover

76 Keysight 8480 Series Operating and Service Manual

EPM Series Power Meter (E4418B) Modification A

4 Figure A-4 shows the power meter with its cover removed.

Figure A-4 Power meter with its cover removed

5 Use the razor blade or craft knife to remove three hole plugs in the rear panel,

as shown in Figure A-5.

Figure A-5 Remove three hold plugs

Keysight 8480 Series Operating and Service Manual 77

A EPM Series Power Meter (E4418B) Modification

6 Figure A-6 shows a different view of the holes in the rear panel.

Figure A-6 Holes in the rear panel

7 Using the three lengths of AWG 20 wire, strip away 2cm from each end of the

wires. Solder an end of each wire onto the screw-fit BNC female connectors, as shown in Figure A-7.

Figure A-7 Solder each wire onto the screw-fit BNC female connectors

78 Keysight 8480 Series Operating and Service Manual

EPM Series Power Meter (E4418B) Modification A

8 Securely fit the three BNC connectors into the three holes in the rear panel, as

shown in Figure A-8. Use the 25 lb/in torque wrench to tighten the nuts.

Figure A-8 Fit the three BNC connectors into the three holes in the rear

panel

9 The Measurement PCB (A6) must now be modified. The call outs in Figure A-9

show where the three wires need to be soldered. Solder a wire into each hole (Chop, Low Gain, and High Gain Outputs). Take care not to over heat the PCB, as this may damage the trace.

Keysight 8480 Series Operating and Service Manual 79

A EPM Series Power Meter (E4418B) Modification

Chop Output

High Gain Output

Low Gain Output

Chop Output

High Gain Output

Low Gain Output

Figure A-9 Location to solder each wire

10 Figure A-10 shows a different view of the modified Measurement PCB.

80 Keysight 8480 Series Operating and Service Manual

Figure A-10 Different view of the modified Measurement PCB

EPM Series Power Meter (E4418B) Modification A

11 Label each of the BNC connectors using the permanent marker and adhesive

labels, as shown in Figure A-11. Refit the cover, handle, and the rear bumper to the power meter. Tighten both screws with the T-15 torque screwdriver.

Figure A-11 Label the BNC connectors with a permanent marker and

adhesive labels

Keysight 8480 Series Operating and Service Manual 81

A EPM Series Power Meter (E4418B) Modification

THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.

82 Keysight 8480 Series Operating and Service Manual

Keysight 8480 Series Coaxial Power Sensors Operating and Service Manual

B Bulkhead Assemblies

This Appendix contains the material lists and exploded graphics of the Bulkhead Assemblies.

B Bulkhead Assemblies

Bulkhead Parts Lists

Tab le B-1 Bulkhead parts for the 8481A, 8481B, 8482B, and 8482B models

Reference designator

MP1 Connector Nut 5021-7255 - 5021-7255

MP2 Connector Component 1250-0016 - 1250-0016

MP3 Connector Body 1250-2132 1250-1466 1250-2132

MP4 Contact Assembly 1250-0917 1250-0816 1250-0917

MP5 Insulator 5040-0306 5040-0306 5040-0306

MP6 Center Conductor - Cartridge Adapter 5020-3296 5020-3296 5020-3296

MP7 Compression Spring 1460-0977 1460-0977 1460-0977

MP8 Sliding Contact 5020-3297 5020-3297 5020-3297

MP9 Bulkhead 08481-20015 08481-20015 08481-20015

MP10 Flat Washer

MP11 Cap Nut 08481-20016 08481-20016 08481-20016

MP12 Polyiron 08481-40006 08481-40006 -

MP13 Protective Cap 1401-0099 1401-0099 1401-0099

MP14 Outer Conductor Spacer

Part description

8481A 8481B

2190-0831 or

3050-0622

5021-0830 or

08742-0006

Sensor model

8481A

Opt 001

2190-0831 or

3050-0622

5021-0830 or

08742-0006

8482A 8482B

5021-0830 or

08742-0006

MP15 Inner Conductor Spacer

A1 Cartridge 08481-60042 08481-60042 08482-60019

5020-8540 or

08742-0005

5020-8540 or

08742-0005

5020-8540 or

08742-0005

84 Keysight 8480 Series Operating and Service Manual

Table B-2 Bulkhead parts for the 8481D model

Bulkhead Assemblies B

Reference designator

MP1 Connector Nut 5021-7255

MP2 Connector Component 1250-0016

MP3 Connector Body 1250-2132

MP4 Contact Assembly 1250-0917

MP5 Insulator 5040-0306

MP6 Center Conductor - Cartridge Adapter 5020-3296

MP7 Compression Spring 1460-0977

MP8 Sliding Contact 5020-3297

MP9 Adapter Connector 08481-20034

MP10 Center Conductor Contact 08481-20032

MP11 Insulator 5040-0306

MP12 Stepped Center Conductor 08481-20033

MP13 Rear Spacer 08481-20029

MP14 Bellows 0955-0238

MP15 Feed Thru Insulator 08486-40001

MP16 Rear Housing 08481-20028

Part description

Sensor model

8481D

MP17 Cap Nut 08486 20007

MP18 Compensation Washer 08481-20031

MP19 Outer Conductor Spacer 5021-0830

MP20 Inner Conductor Spacer 5020-8540

MP21 Inner Conductor Spacer 08742-0005

MP22 Outer Conductor Spacer 08742-0006

A1 Cartridge 08481-60041

H1 Flat Washer 2190-0831 or 3050-0622

Keysight 8480 Series Operating and Service Manual 85

B Bulkhead Assemblies

Tab le B-3 Bulkhead parts for the 8481H and 8482H models

Reference designator

MP1 Connector Nut 5021-7255 5021-7255

MP2 Connector Component 1250-0016 1250-0016

MP3 Connector Body 1250-2132 1250-2132

MP4 Contact Assembly 1250-0917 1250-0917

MP5 Insulator 5040-0306 5040-0306

MP6 Center Conductor - Cartridge Adapter 5020-3296 5020-3296

MP7 Compression Spring 1460-0977 1460-0977

MP8 Sliding Contact 5020-3297 5020-3297

MP9 Housing 08492-2000 08492-2000

MP10 Attenuator Adapter 5021 0154 5021 0154

MP11 Sliding Contact 5020-3297 5020-3297

MP12 Compression Spring 1460-1547 1460-1547

MP13 Contact Holder 5021-0157 5021-0157

MP14 Insulator 5040-0306 5040-0306

MP15 Center Conductor - Cartridge Adapter 5020-3296 5020-3296

MP16 Compression Spring 1460-0977 1460-0977

Part description

8481H 8482H

Sensor model

MP17 Sliding Contact 5020-3297 5020-3297

MP18 Bulkhead 08481-20015 08481-20015

MP19 Cap Nut 08481-20016 08481-20016

MP20 Protective Cap 1401-0099 1401-0099

MP21 Polyiron 08481-40006 -

MP22 Flat Washer 3050-0622 3050-0622

MP23 Flat Washer 3050-0622 3050-0622

MP24 Outer Conductor Spacer 5021-0830 or 08742-0006 5021-0830 or 08742-0006

86 Keysight 8480 Series Operating and Service Manual

Table B-3 Bulkhead parts for the 8481H and 8482H models

Bulkhead Assemblies B

Reference designator

MP25 Inner Conductor Spacer 5020-8540 or 08742-0005 5020-8540 or 08742-0005

MP26 Flat Washer 2190-0831 or 3050-0622 -

A1 Cartridge 08481-60042 08482-60019

A2 Cartridge Assembly 08481-60011 08481-60011

Part description

8481H 8482H

Sensor model

Table B-4 Bulkhead parts for the 8483A model

Reference designator

MP1 Connector Nut 5021-7255

MP2 Connector Component 1250-0016

MP3 Connector Body 1250-2132

MP4 Center Conductor, 75 Ohm 08483-20003

MP5 Insulator 5020-8593

MP6 Center Contact, 75 Ohm 08483-20002

MP7 Compression Spring 1460-0526

Part description

Sensor model

8483A

MP8 Sliding Contact 08491-2009

MP9 Bulkhead 08481-20015

MP10 Inner Conductor Spacer 00909-20006

MP11 Cap Nut 08481-20016

MP12 Information Label 7120-4351

MP13 Protective Cap 1401-0099

MP14 Outer Conductor Spacer 5021-0830 or 08742-0006

A1 Cartridge 08483-60010

Keysight 8480 Series Operating and Service Manual 87

B Bulkhead Assemblies

Tab le B-5 Bulkhead parts for the 8485A and 8485D models

Reference designator

MP1 Connector Nut 08485-20005 08485-20005

MP2 Connector Component 1250-0016 1250-0016

MP3 Bulkhead 08485-20011 08485-20011

MP4 Outer External Coax 5021-7092 5021-7092

MP5 Outer Conductor Spacer 00281-20046 00281-20046

MP6 Center Conductor 5040-6958 5040-6958

MP7 Center Internal Coax 5021-7093 5021-7093

MP8 Bellows 0955-0238 0955-0238

MP9 Outer Internal Coax 5021-7091 5021-7091

MP10 Bellows Spacer 5021-9206 5021-9206

MP11 Matching Washer

MP12 Feed Thru Insulator 08486-40001 08486-40001

MP13 Cap Nut 08486-20007 08486-20007

A1 Cartridge 08485-60015 08481-60041

Part description

8485A

8485A Opt 033

5021-7094 or 08485-20024

Sensor model

8485D

8485D Opt 033

5021-7094 or 08485-20024

C1 Fixed Capacitor, 1300Pf 50v 0160-4746 0160-4746

88 Keysight 8480 Series Operating and Service Manual

Table B-6 Bulkhead parts for the 8487A and 8487D models

Bulkhead Assemblies B

Reference designator

MP1 Connector Nut 5021-7081 5021-7081

MP2 Connector Component 1250-0016 1250-0016

MP3 Bulkhead 08487-20001 08487-20001

MP4 Outer External Coax 08487-20002 08487-20002

MP5 Pin Depth Washer 08487-00001 08487-00001

MP6 Center Contact 1250-2115 1250-2115

MP7 Bead Ring Assembly 1250-2107 1250-2107

MP8 Internal Center Conductor 08487-20003 08487-20003

MP9 Bellows 0955-0333 0955-0333

MP10 Outer Internal Coax 08487-20004 08487-20004

MP11 Matching Washer

MP12 Matching Washer

MP13 Polyiron - 08673-20046

MP14 Feed Thru Insulator 08486-40001 08486-40001

MP15 Cap Nut 08486-20007 08486-20007

Part description

8487A 8487D

08487-20006,

08487-20005, or

08487-20007

08487-20011 or

5022-2866 or 5022-2878

or 5022-3611

Sensor model

08487-20006,

08487-20005, or

08487-20007

08487-20011 or

5022-2866 or 5022-2878

or 5022-3611

A1 Cartridge 08487-67110 08487-60004

C1 Fixed Capacitor, 1700Pf 50v 0160-6978 0160-6978

Keysight 8480 Series Operating and Service Manual 89

B Bulkhead Assemblies

Bulkhead Exploded Graphics

Figure B-1 8481A and 8481B

90 Keysight 8480 Series Operating and Service Manual

Bulkhead Assemblies B

Figure B-2 8481A Option 001

Keysight 8480 Series Operating and Service Manual 91

B Bulkhead Assemblies

Figure B-3 8482A and 8482B

92 Keysight 8480 Series Operating and Service Manual

Bulkhead Assemblies B

Figure B-4 8481D

Keysight 8480 Series Operating and Service Manual 93

B Bulkhead Assemblies

8481H Only

Figure B-5 8481H and 8482H

94 Keysight 8480 Series Operating and Service Manual

Bulkhead Assemblies B

Figure B-6 8483A

Keysight 8480 Series Operating and Service Manual 95

B Bulkhead Assemblies

Figure B-7 8485A, 8485A Opt 033, 8485D, and 8485D Opt 033

96 Keysight 8480 Series Operating and Service Manual

Bulkhead Assemblies B

Figure B-8 8487A and 8487D

Keysight 8480 Series Operating and Service Manual 97

B Bulkhead Assemblies

THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.

98 Keysight 8480 Series Operating and Service Manual

This information is subject to change without notice. Always refer to the English version at the Keysight website for the latest revision.

Printed in Malaysia

*08481-90173*

08481-90173

www.keysight.com

Keysight Technologies 8481A, 8480 Series, 8483A, 8485A, 8487A Operating And Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Notice

Warranty

Manufacturer's Declaration

Hersteller-bescheinigung

Regulatory Markings

Sales and Technical Support

Table of Contents

List of Figures

List of Tables

1 Introduction

General Information

Instruments Covered by Manual

Description

Dimensions

8480 series, B-models information

8480 series, Options

Recommended Calibration Interval

8480 Series Power Sensor Specifications

Supplemental Characteristics

Installation

Initial Inspection

Storage and Shipment

Operation

Environment

Operating Precautions

2 General Information

Connector Care

Torque

Performance Test

Voltage standing wave ratio (VSWR) and reflection coefficient (Rho) performance verification test

Zero set performance verification

Power linearity performance verification

Adjustments

Replaceable Parts

3 Service

Principles of Operation

Thermocouple sensors

Diode sensors

Troubleshooting

Troubleshooting - eliminating the power meter and sensor cable

Troubleshooting - power sensors

A1 Bulkhead (thermocouple sensors)

Repair

A1 Bulkhead Assembly

A2 Power Sensor Board Assembly

FET Balance Adjustment

Equipment Required

Test Description

FET Balance Procedure

Disassembly / Reassembly Procedures

Disassembly Procedure

Reassembly Procedures

The Material and Tools Required

Impact on Warranty

Modification Procedure

B Bulkhead Assemblies

Bulkhead Parts Lists

Bulkhead Exploded Graphics