Agilent 8720C Supplement to User’s and Service Guides

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Agilent Technologies

8720C Option H85

Vector Network Analyzer

Supplement to User’s and Service Guides

Use this supplement with instruments

having a Serial Number Prefix of 3124A or higher.

Use this supplement with the following documents:

8720C User’s Guide

Part Number 08720-90157

8720C Service Guide

Part Number 08720-90138

Agilent Technologies Part Number: 08720-90163

Printed in USA November 2001

Notices

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(including electronic storage and retrieval or translation into a foreign
language) without prior agreement and written consent from Agilent
Technologies, Inc. as governed by United States and international
copyrigh t laws.

Restricted Rights Legend

Use, duplication, or di sclosure by the U.S. Government is subject to
restrictions as set forth in subparagraph (c)(1)(ii) of the Rights in
Tec hni cal Data and Computer Softw ar e clau se at DFARS 252.227-7013
for DOD agencies, and subparagraphs (c)(1) and (c)(2) of the
Commercial Computer Software Restricted Rights clause at
FAR 52.227-19 for other agencies.

Warranty

The material contained in this document is subj ect to change without
notice. Agilent 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 partic ular purpose. Agilent
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.

Agilent Technologies, Inc.
1212 Valley House Drive
Rohnert Park, CA 94928-4999, U.S.A.
© Copyright 2000 Agilent Technologies, Inc.

4

Contents

1. User’s Guide Supplement

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

Bypass Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

SCMM Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5

High Power Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

Setup Considerations for Avoiding Instrument Damage . . . . . . . . . . . . . . . . 1-7

Operating in a Single Frequency Band. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7

Operating in Multiple Frequency Bands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

Attenuators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

2. Service Guide Supplement

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Material List Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Contents-1

Contents-2

1 User’s Guide Supplement

Supplement to User’s and Service Guides 1-1

Agilent Technologies 8720C Option H85

1-2 Supplement to User’s and Service Guides

Agilent Technologies 8720COption H85

Introduction

Introduction

The Agilent 8720C Option H85 is a modified version of the standard
Agilent 8720C Vector Network Analyzer. The purpose of Option H85 is
to provide high-power measurement capability.

This document describes Option H85 operating features and
performance specifications th at diff er from those of the stand ard 8720C

Network Analyzer. Refer to the 8720C User’s Guide (Agilent Part No.
08720-90157) for all other features and specifications.

The 8720C Option H85 has three different operating configurations:

• Bypass

• Single Connection Multiple Measurement (SCMM)

• High Power

All three configurations have a frequency range of 50 MHz to 20 GHz.

NOTE The instrument is shipped fr om the facto ry in the By pass configuration.

(Jumper cables are installed on the front and rear panels as shown in
Figure 1-1.)

NOTE The internal software has not been modified for Option H85. Power

levels indicated on the instrument may differ depend ing on which user
configuration is chosen.

Supplement to User’s and Service Guides 1-3

Agilent Technologies 8720C Option H85

Bypass Configuration

Bypass Configuration

This configuration allows the instrument to operate as a normal 8720C
with degraded source power specs. This configuration is illustrated in
Figure 1-1. The source power specs are listed in Table 2-1 on page 2-2.

Figure 1-1 Bypass Configuration

1-4 Supplement to User’s and Service Guides

Agilent Technologies 8720COption H85

SCMM Configuration

SCMM Configuration

This configuration is provided by means of RF conne ctors for the source
path on the instrument rear panel and RF connectors for each test port
coupler through-path on the front panel. This configuration is
illustrated in Figure 1-2.

Figure 1-2 Single Channel Multiple Measurement (SCMM) Configuration

Supplement to User’s and Service Guides 1-5

Agilent Technologies 8720C Option H85

High Power Configuration

High Power Configuration

This configuration is the primary one that Option H85 was designed to
provide. It allows high-power network measure ments at RF levels up to
20 Watts (+43 dBm). This configuration is illustrated in F igure 1-3.

Figure 1-3 High Power Configuration

CAUTION It is highly recommended that the user verify the RF power levels seen

by the various elements of the test setup pr ior to poweri ng-up the d rive
amplifier. At high power levels, a mistake could permanently damage
the network analyzer. Consult Table 1-1.

1-6 Supplement to User’s and Service Guides

Table 1-1 Key Power Levels

Recommended Max. RF Level at A/B/R Samplers −10 dBm
Absolute Maximum RF Level at A/B/R Samplers +10 dBm
Damage Level at A/B/R Samplers +20 dBm
Damage Level to F/R Transfer Switch +30 dBm
Damage Level to Port 1 and Port 2 Couplers +47 dBm

Setup Considerations for Avoiding Instrument
Damage

• A high-power isolator or attenuator MUST be inserted at the Port 1
front panel jumper and at the Port 2 front panel jumper to protect
the F/R transfer switch. 30 dB o f isolation is re c o m mended.

• Optimum power level at samplers is -10 dBm. Adjust step
attenuators at A/B samplers accordingly.

Agilent Technologies 8720COption H85

High Power Configuration

• Set initial instrument state to -65 dBm test port power level to
reduce the risk of damage when turning on the unit. Recommended
sweep mode is [STEP].

• 10 to 12 dB of attenuation in the rear panel reference path is
recommended.

Operating in a Single Frequency Band

For high-power, limited frequency band applications the External
Reference Mode must be used. To activate this mode, press [SYSTEM],
then press [INSTRUMENT MODE], then press the
EXT R CHAN ON/OFF softkey until ON

NOTE “Rex” (meaning Referenc e e x te r n a l ) w i ll b e displayed on the left sid e of

the CRT indicating that the External Reference Mode has been
selected.

NOTE The external reference channel on/off softkey (EXT R CHAN ON/OFF)

is GPIB addre s s a b le. T h e pr oper mnemoni cs are “exterchanon” and
“exterchanoff”.

is selected.

Once the External Reference Mode has been selected, a coupler with the
frequency range of interest must be installed between the drive
amplifier and the RF IN connector on the rear panel. Also, an
appropriate attenuator must be inserted between the coupled arm and
the REF IN connector to ma i n ta i n the proper R F le vel to the reference
sampler. (See Figure 1-3.)

Supplement to User’s and Service Guides 1-7

Agilent Technologies 8720C Option H85

High Power Configuration

Operating in Multiple Frequency Bands

The design of the Option H85 allows the R sampler to receive a portion
of the RF signal from either the internal source prior to the RF OUT
port or from the external REF IN connector on the rear panel. This is a
requirement of the High P ower configuration because the phaselock
search of the 8720C responds to ce rtain cardinal freque ncies which may
be outside the range of the amplifier.

Attenuators

Additional programmable step attenuators provide up to 70 dB of
attenuation in 10 dB steps. These attenuators are located before the A
and B samplers (see Figure 1-3) to protect them f rom hig h power levels
and to keep them ope rating at le vels below
are designed to be controlled by an Agilent Model 11713A Attenuator /
Switch Driver with connections made at the instrument real panel
labeled Port 1 A TTEN DRIVE and Port 2 ATTEN DRIVE. Table 1-2
indicates the level of attenuation achieved for each 11713A setting.
Refer to the 11713A manual for GPIB program codes and operating
information.

−10 dBm. These attenuators

NOTE These attenuators have no impact on actual tes t port power.

See Figure 1-3.

Table 1-2 Attenuation Levels for Various 11713A Settings

11713A

Pushbutton

Attenuator

X

Selection

Attenuator

Y

Selection

NOTE The attenuation values shown in Table 1-2 are additive for multiple

1
2
3
4

5
6
7
8

Attenuation

in dB

10
20
20
20

10
20
20
20

pushbutton selections.

1-8 Supplement to User’s and Service Guides

2 Service Guide Supplement

Supplement to User’s and Service Guides 2-1

Agilent Technologies 8720C Option H85

Specifications

Specifications

Table 2-1 lists Option H85 specifications that differ from those of the
standard instru ment.

Table 2-1 Option H85 Source Power Specs (Supplemental to 8720C)

Frequency Range

Parameter

50 MHz

Maximum Power +10 dBm +5 dBm
Power Flatness ±2.5 dB ±5 dB

− 8 GHz 8 GHz − 20 GHz

a.At 23 ±3 °C

a

2-2 Supplement to User’s and Service Guides

Agilent Technologies 8720COption H85

Material List Changes

This section lists the repl aceabl e parts that are delet ed f rom and a dde d
to the standard instrument in order to build the 8720C Optio n H85.

Table 2-2 Replaceable Parts Deleted for 8720C Option H85

Material List Changes

Reference

Designator

16 DRESS PANEL 08720-80035 1
17 SUB PANEL 08415-00052 1

NS REAR PANEL, LOWER 08720-00027 1

A60, 61 BIAS TEE 5086-7458 2

W22 CABLE A63 TO A66 08415-20071 1
W23 CABLE A58 TO RR PNL 08720-20082 1
W25 CABLE A62 TO A61 08415-20069 1
W26 CABLE A63 TO A60 08415-20068 1
W27 CABLE A60 TO S4 08415-20081 1
W28 CABLE A61 TO S4 08415-20081 1
W29 CABLE S4 TO A69 08720-20076 1
W33 CABLE A64 TO RR PNL 08720-20073 1

Description

Part

Number

Quantity

Supplement to User’s and Service Guides 2-3

Agilent Technologies 8720C Option H85

Material List Changes

Table 2-3 Replaceable Parts Added for 8720C Option H85

Reference

Designator

W50 CABLE S5J1 TO REFIN RR PNL 08720-20080 1
W51 CABLE S5J2 TO A58 08720-20077 1
W52 CABLE S5J3 TO A64 08720-20078 1

16 DRESS PANEL 08720-00051 1

17 SUB PANEL 08720-00052 1
NS REAR PANEL, LOWER 08720-00053 1
NS ATTEN BRKT (A70, 71) 08720-00054 2
NS 3.5 BLKHD CONN F (FRNT, RR PNLS) 5062-6618 4
NS WSHR-LK 2190-0104 4
NS NUT-HEX 2950-0132 4

W53 CABLE A69 TO RFOUT RR PNL 08720-20086 1
W54 CABLE S4-C TO RFIN RR PNL 08720-20087 1
W55 CABLE S4-2 TO A PORT1 FPNL 08720-20090 1

Description Part

Number

Quantity

W56 CABLE S4-1 TO A PORT2 FPNL 08720-20091 1
W57 CBLE B PORT1 FPNL TO A62 08720-20092 1
W58 CABLE B PORT2 FPNL TO A63 08720-20093 1
W59 CBLE A62 TO A70 08720-20094 1
W60 CABLE A63 TO A71 08720-20095 1
W61 CABLE A70 TO A65 08720-20096 1
W62 CABLE A71 TO A66 08720-20097 1
W63 CABLE JUMPER 08720-20075 2
W64 RIB CA A70 TO RPNL PORT1 ATTEN DRV 08720-60085 1
W65 RIB CA A71 TO RPNL PORT2 ATTEN DRV 08720-60086 1

A70,71 PROGRAMMABLE ATTENUATOR 70 DB 33321T 2

S5 M-WAVE SWITCH (REFLOCK SELECT) 08415-60057 1

W66 WIRE HARNESS (S5 CONTROL) 08720-60093 1

A9 CPU BD ASSY (MOD 08720-60040) 08720-60090 1

2-4 Supplement to User’s and Service Guides