Agilent Technologies 85301B Manuel utilisateur

Agilent 85301B/C

Antenna Measurement Systems

45 MHz to 110 GHz

Configuration Guide

Table of Contents

3 Introduction

4 How to use this guide

4 General range parameters

4 Transmit site configuration

6 Range transfer function

7 Required measurement sensitivity

8 Selecting the system

10 85301B Antenna Measurement System

10 System configurations

12 Selecting the LO source

13 Reference signal level

13 Calculating reference power

14 Interconnect cables

19 RF cable ordering information

21 85301C Antenna Measurement System

21 IF interconnect cable

21 RF cables

21 Radiated reference signals

21 Reference phase-lock signal power level

22 Coupled reference signals

22 GPIB cables

22 GPIB extenders

23 Optional Capabilities

23 Manual antenna measurements

24 Measurement automation software

24 Millimeter-wave configuration

26 Multiple test channel configuration

27 Antenna positioning systems

29 Configuration Diagrams

29 General antenna range information

30 Transmit site configuration

31 85301B block diagram configuration

32 85301C block diagram configuration

32 Measurement automation

33 Millimeter-wave subsystem

34 Multiple-channel IF switching configuration

34 Multiple-channel RF switching configuration

35 Positioner configurations

Introduction

This Antenna Measurement Systems Configuration

Guide will help you configure a custom Agilent

Technologies 85301 or 85301C antenna measure-

ment system that meets your measurement

requirements. This guide is primarily for those cus-

tomers who desire to design, integrate, and install

their own antenna measurement systems using

Agilent antenna test instrumentation. The guide

will lead you through all the steps. For the do-it-

yourself customer, this guide will assist you in

determining what instrumentation to order from

Agilent Technologies. Your Agilent Technologies

sales engineer will be glad to assist you in procur-

ing the instrumentation. If desired, technical assis-

tance is available from systems engineers who are

experienced in configuring antenna measurement

systems.

Some customers may prefer the design, integra-

tion, and installation of an antenna instrumenta-

tion subsystem be performed for them by a solu-

tion supplier who has extensive antenna configura-

tion experience. Nearfield Systems, Inc. (NSI), an

Agilent Technologies channel partner, can provide

this service. NSI will work with you to understand

your measurement needs, and then design an RF

subsystem that meets your requirements. In addi-

tion to system design and configuration, NSI pro-

vides system integration, on-site installation, and

performance verification to ensure that the system

delivered meets your requirements. NSI will pro-

vide a complete RF subsystem, reducing your risk,

and eliminating the need for your personnel to

design and configure a system.

Other customers may need an application solution:

a complete system solution that addresses all

aspects of a measurement application, such as a

complete near-field or far-field measurement sys-

tem. You may be designing, building, and testing

antennas instead of an antenna measurement sys-

tem. Agilent Technologies recommends Nearfield

Systems, Inc. for complete near-field and far-field

application solutions. NSI has the measurement

expertise to supply a complete system to meet

your application requirement. NSI can configure

and supply the RF subsystem, the positioning sub-

system, provide the measurement application soft-

ware, and provide system installation and training.

If you choose to use NSI’s services, you will not

need to use this configuration guide; NSI will care-

fully consider all the issues covered in this configu-

ration guide. Your Agilent sales engineer has a

technical qualification guide that can be used to

help define your measurement requirements, and

he or she will be happy to work with you to define

your requirements. Your sales engineer can also

assist you in contacting NSI, or you can contact

NSI directly (California, USA) at (310) 518-4277,

FAX (310) 518-4279, by e-mail: [email protected],

or visit their extensive website at www.nearfield.com.

Main parts of an antenna range

In general, an antenna range measurement system

can be divided into two separate parts: the trans-

mit site and the receive site (see Figure 1). The

transmit site consists of the microwave transmit

source, amplifiers, and the communications link to

the receive site. The receive site consists of the

receiver, LO source, RF downconverter, positioner,

system software, and a computer.

Figure 1. Far-field antenna range

TRANSMIT SITE

• Synthesized Sweeper

• Amplifers

RECEIVE SITE

• Receiver • Positioner

• LO Source • Computer

• RF Downconverter

Configuration steps

Configuring an Agilent 85301 /C antenna mea-

surement system involves the following steps. Each

step is described in detail in this guide.

1. Select the transmit source, amplifiers, cables

and method used to obtain the reference channel

signal, and determine the minimum transmit

power.

2. Determine the worst-case antenna range transfer

function based on range length, maximum test fre-

quency, and transmit antenna gain.

3. Calculate the estimated test channel power level

based on transmit power, range transfer function,

and expected test antenna gain.

4. Determine required measurement sensitivity

based on test channel power level, required mea-

surement dynamic range, and accuracy.

5. Select either an 85301 or 85301C antenna mea-

surement system depending on range type and

required microwave performance.

6. Configure the receive site.

7. Calculate the reference channel power level.

8. Review the complete configuration for accuracy

and completeness.

9. You may wish to review the completed configu-

ration with your Agilent Technologies sales repre-

sentative and/or systems engineer, or with

Nearfield Systems, Inc.

How to use this guide

You can use Figures 16 through 25 at the end of

this guide as worksheets for configuring your

antenna measurement system. The bubble numbers

in these figures (example: ) indicate that a

value should be entered. These numbers corre-

spond directly with the bubble numbers by the

instructions in this guide. We recommend that you

photocopy Figures 16 through 25 and fill them in

as you go through the instructions.

General range parameters

Record the range type and length in Figure 16.

If a compact antenna test range (CATR) is to be

used, record the manufacturer and model number.

Transmit site configuration

The following steps are required to configure the transmit

site:

• Select the transmit source.

• Determine RF cable losses and transmit power

based on range type.

• Decide how the reference channel signal will be

obtained.

Transmit source selection

Record the required minimum and maximum

test frequencies for the antenna range in Figure 17.

ased on these frequency requirements, select a

transmit source from Table 1 below, check the

model number in Figure 17, and record its maximum

output power level at the upper test frequency on

Figure 17. Agilent recommends using only sources

with front panel controls; this will allow diagnos-

tics to be performed on the system if necessary.

The 1 Hz frequency resolution (Option 008) is

recommended for both the RF and LO sources to

allow the frequency resolution to be 1 Hz instead

of 1 kHz. While most users desire a 1 Hz frequency

resolution, it has the additional benefit of ensuring

that the signal presented to the receiver is within

its passband. If the system is to be used for mea-

suring antennas in pulsed mode of operation, fast

pulse modulation (Option 006) should be ordered.

Table 1. Agilent 85301B/C compatible transmit sources

Model Output

Number Description Power (dBm)

83620B 10 MHz to 20 GHz synthesized +13 dBm

sweeper with front panel controls.

Recommended options: Option 004,