Agilent 8530A User's Guide

HP 8530A Microwave Receiver

User's Guide

ABCDE

No

art

P

HP

.A.

.S

U

Printed

in

Edition

08530-90016

.

ebruary

F

3

1994

Notice

This document contains proprietary information which is protected by copyright. All rights are

reserved. No part of this document may be photocopied, reproduced, or translated to another

language without prior written consent of Hewlett-Packard Company.

NOTE: Figure A-1 and Figure A-3 may be photocopied for use by the operator of the HP 8530A.

These gures may not be reproduced in other documents.

Hewlett-Packard Company

Santa Rosa Systems Division

1400 Fountaingrove Parkway

Santa Rosa, CA 95403, U.S.A.

c



1992,

1993,

1994

Hewlett-P

ackard

Co

.

Printing History

New editions of this manual will incorporate all material updated since the previous editions.

The manual printing date and part number indicate its current edition. The printing date

changes when a new edition is printed. (Minor corrections and updates which are incorporated

at reprint do not cause the date to change.) The manual part number changes when extensive

technical changes are incorporated.

Edition Date

Edition 1 October 1991

Edition 2 May 1992

Edition 3 October 1993

Manual Applicability

This manual applies directly to HP 8530A Receivers having an HP 85102R IF detector with

serial

number

prex

3238A

or

higher

running

,

rmware

revision

A.01.60

W

Safety

,

warranty

,

Programming

arning

W

Caution

Regulatory

arranty

and

,

Manual

Before

grounded

socket

Any

outside

can

,

regulatory

.

instrument

this

through

outlet

provided

interruption

the instrument,

result in

personal injury

information

the

of

Before this instrument is switched on,

Information

supplied

is

make

,

is switched

on

protective conductor

with protective

the protective

(grounding) conductor

or disconnection

.

make sure its primary power circuitry

8530A

HP

the

in

it

sure

the

of

earth contact.

of the

protective earth

has

ac

power

Operating

properly

been

cable

inside

,

and

to

or

terminal

has been adapted to the voltage of the ac power source.

Failure to set the ac power input to the correct voltage could cause damage to

instrument

the

when

the

ac

power

cable

plugged

is

in.

a

iii

Instrument Overview

For more information on instrument controls, refer to \Front Panel Overview" in Chapter 1 and

\Front and Rear Panel" (Chapter 3) in the

HP 8530A Operating and Programming Manual

.

Overview

messages.

It also

shows the

names of

Display

1.

display

The

display

shows

softkeys

measurement

.

Figure

results

Instrument

0-1.

and

information

2. Softkeys

Many functions are controlled by softkeys. The title of each softkey is displayed on the display.

Entry

3.

The entry

Enter numeric values using

Terminate values with appropriate units

or milli),

Increase or decrease values using the

Correct errors using the

Go

Turn

Block

block allows you to:

4

5

(basic units),

x1

of

level

one

up

active

the

OFF

4

softkey

function

the keypad

BACKSPACE

menus by

pressing

by

485

5

key.

pressing

4

5

through

0

4

5

(giga or nano),

G/n

and

495

4

ENTRY

4

5,4

5

+/-

.

4

5

(mega or micro),

M/u

9

keys, or using the rotary knob.

.

5

MENU

PRIOR

.

5

OFF

4

k/m

5

(kilo

iv

4. Status Display

This diagnostic/status display has the characters R L T S 8 4 2 1 in it. This display shows the

HP-IB Remote (R), Listen (L), or Talk (T) status, or shows if a service request \SRQ" has been

asserted (S). The numbers are self-test indicators.

5. Disc Drive

The disc drive accepts 3.5 inch DOS or Hewlett-Packard LIF format disks. Either 720 kB or

1.44 MB DOS disks can be used. The HP 8530A can show disc contents, format in DOS or LIF

format, delete les, or undelete the last le deleted (undelete works on LIF format discs only).

6. TEST Button

Causes self tests to be performed on the receiver.

7. AC power switch

This switch applies AC power to the Display section (turn this ON after the power switch on

10).

item

see

the

bottom

box,

Channel

8.

two

The

parallel

features

displayed

Menus

9.

Contains

controls

4

5

CAL

4

DOMAIN

4

DISPLAY

4

MARKER

data

Select

the

channels

independently

separately

several

selects

5

selects how many dierent measurements to display on the screen at once.

5

allows you to use the marker features of the instrument.

make

processing

or

,

major

three

Angle

pathways

of

they

functions

dierent

,

10. AC power switch

power

C

This

switch

applies

A

measurement,

same

.

other

the

be

can

types

Frequency

to the

channel

Each

channel.

overlaid

measurement

of

Time

or

,

bottom

and

allows

nal

The

the

on

Domain

section.

split

then

you

results

graticule

same

calibration.

operation.

to

the

apply

from

raw

dierent

each

.

data

channel

results into

instrument

be

can

two

v

11. Instrument State

Contains several functions:

4

5

LOCAL

allows you to specify the HP-IB addresses of the receiver and \slave" instrument

connected to the System Interconnect. (The System Interconnect is the HP 8530A's

\personal" HP-IB bus. Any devices connected to it (printers, plotters, RF or LO sources) are

controlled exclusively by the HP 8530A.

4

5

and

SAVE

4

RECALL

5

allow you to save current measurement settings to one of eight save/recall

registers (for later recall).

4

USER PRESET

time you turn power ON or press

5

any setup you save in save register 8 becomes the \user preset" state. Any

4

USER PRESET

5

the settings stored in register 8 are retrieved.

12. Stimulus Block

The stimulus block controls most of the functions associated with the basic measurement setup.

Stimulus controls include:

Measurement start/stop or center/span values for angle, frequency,ortime.

ower

P

Sweep

Number

for

levels

(single

type

measurement

of

RF

and

sweep

sources

LO

continuous

,

points

.

Frequency

(in

sweeps

ramp sweep

,

Domain),

sweep,

,step

increment angle

or

and more).

(in Angle

Domain).

.

setup

mode

selects

select

5

4

measured,

any

the

on

List

(internal,

osition

P

Encoder

which

dierent

and

measurement

four

the

of

b1,

a2,

a1,

external,

controls

8530A

HP

\ratioed"

are

then

results

input

b2

or

HP-IB).

or

.

measure

inputs

to

measurements

mathematically

.

lines

Softkey

lines

menus

without

.)

main keys

the

.

\Ratio"

.

divided

under

means

together

this

ratioing. (This

4

ARAM

P

test

a

that

method provides

This

.

block's

4

MENU

feature allows

through

5

1

and reference

allows

key

5

you to

check the

you

Frequency

Trigger

85370A

HP

arameter Block

P

13.

block

This

4

ARAM

P

are

signal

accurate

very

measure

to

signals

14. Auxiliary Menu

This area contains three control keys:

4

COPY

4

DISC

allows

5

allows

5

disc-related

4

SYSTEM

are controlled are: phase lock, IF calibration,

you

to save

drive

disc

the

use

to

you

functions

5

contains instrument conguration functions

.

or

power leveling, and multiple-source setup

measurement results

the

plot

or

print

to

(used when more than one source is connected to

load

the HP 8530A). The system key also has

.

format

,

les

Examples of the type of functions that

.

service menus that are used when troubleshooting the instrument.

15. Format Block

as

This block

allows

you

to

select

dierent

display

formats

such

log format.

vi

discs

Cartesian

,

and

or

perform

polar

other

or

linear

in

,

16. Response Block

This block controls the following:

Display scale

Position and value of the reference line

Automatic display scale (autoscale)

Measurement averaging

Trace smoothing

Trace \normalization" (A specic point on the measurement trace is set to 0 dB, and other

portions of the trace are displayed relative to that.)

Magnitude slope and oset control

Phase oset control

Coaxial, waveguide, or user-denable electrical delay selection

17.

4

RESTART

5

This

progress

in

key

is

used

If

.

when

you

are

you

using

are

making

the

single

swept

sweep

measurements

4

,

mode

REST

ART

.

It

5

can

aborts

start

measurement

any

new

a

sweep

that is

.

vii

Guide to this Manual

Guide

receiver

display

,

Chapter

8530A

features

Chapter

Figure

cquainted

quick

a

A

overview

1.

provides

1

Getting

.

Manual Measurement

2.

0-2. Sections

with

the

of

HP

the

in

HP

the

panel

front

Examples

8530A

controls

User's

Chapter 2 shows very basic antenna and RCS measurement examples.

Chapter 3. Calibration

how

Chapter

describes

3

calibration

the

features

of

the HP

8530A,

and

Chapter 4. Measurement Tutorials

This chapter gives more in-depth information on making measurements

explained

how to use

so you can customize measurements to suit your needs

the HP 85370A P

osition Encoder

.

. This chapter also explains

.

panel,

rear

,

them.

use

to

eature choices are

.F

and

HP

viii

Chapter 5. Common Measurement Tasks

Chapter 5 describes specic measurement tasks such as:

Finding boresight Using Markers

Determining 3 dB beamwidth Measuring depth of a null

Displaying data relative to the peak Displaying more than one trace

Using averaging Using frequency list mode

Chapter 6. Disc Drive Operation

Explains how to use the built-in disc drive to store and retrieve data, instrument state les,and

other types of information.

Chapter 7. Printing and Plotting

Describes how to output screen \snapshots" or tabular data to printer or plotter. A wide range

of HP printers and plotters are covered in detail.

Chapter

use

to

how

receiver

Making

8.

explains

8

ast

F

the

automatically

to

utomated

A

measure

to

how

Multiplexing.

IF

switch

between

Measurements

5,000 points

up to

multiplexing

IF

ast

(F

dierent

per second

input

similar

is

ratios

at

using F

F

to

angle

each

CW

ast

ast CW

mode

,but

frequency

or

and

,

allows

the

point.)

Diculty

Chapter

chapter

This

solve

to

How

to

What

solve

to

How

Appendix

In

9.

explains:

when

do

A,

common

basic

Case

Optimizing

of

operation

specic

hardware

messages

error

problems

Dynamic

problems

.

displayed

are

Range

on

the

screen.

Conguring the system for optimum dynamic range entails using the highest RF power settings

possible without overdriving the receiver. Appendix A explains how to congure your system

so optimum dynamic range is available.

Compatible

,

Appendix

compatible

Lists

B

RF

and

plotters, and monitors

and P

converters

LO

Instruments

sources,

frequency

.

eripherals

positioner

,

controllers

printers

,

ccessories, After-Sale Options

Appendix C, Supplies

Lists commonly-needed supplies (plotter pens

,A

, paper

, discs) and after-purchase options (time

domain option, rack-mount hardware, connector savers, and touch-up paint).

Appendix

Explains

connector

Connector

,

D

care

Care

techniques

and

cleaning

procedures

.

ix

Other Manuals that Come with the HP 8530A

The following manuals are supplied with the HP 8530A:

Operating and Programming Manual

The Operating and Programming manual serves two purposes:

It provides in-depth reference information on front panel features, organized around the

front panel functional blocks.

It provides tutorial information on remote programming, with many HP BASIC examples.

Keyword Dictionary

The Keyword Dictionary explains:

The function of each front panel key or display softkey, organized by key/softkey name.

What each HP-IB programming code does, including syntax and programming sequence

details.

panel

Front

alphabetical

On-Site

The

Service

On-Site

Installation

Troubleshooting

Performance

Typeface

Bold

Italics

Computer

Display

4

anel Keys

Front P

NNNNNNNNNNNNNNNNNNNNNNNN

NNNNN

Soft Keys

key/softkey

.

order

and

Manual

tests

Manual

specications

and

Service

Conventions

Bold type is used for terms that are listed in the glossary.

Italic type is used for emphasis and for the titles of manuals and other

publications. It is also used when describing a computer

Computer

Display

receiver's

5

Front panel keys are enclosed in

Soft keys are the keys on the right-hand side of the display

function of

programming

contains:

type

is

type

display

these keys changes depending on the menu you are in.

code

used

is

used to

.

descriptions

depict

to

messages

show

coexist

HP-IB

boxes.

the

in

commands

which

are

section,

same

variable

.

displayed

the

on

.The

in

.

x

Getting Acquainted with the HP 8530A Receiver

Chapter Contents

Product Description

Receiver Performance

Measurement Features

Input/Output Features

Principles of Operation

Front Panel Overview

1

Getting

Acquainted with

the

HP

8530A

Receiver

1-1

Product Description

The HP 8530A is a high-performance receiver that has been designed specically for antenna

and radar cross section (RCS) measurements.

The HP 8530A allows you to make angle-scan and frequency-scan measurements of antennas,

or make RCS measurements using the time domain feature.

Very fast measurement speeds are possible with the HP 8530A. By using a computer controller,

the receiver can measure up to 5,000 data points per second.

The receiver has very high sensitivity and dynamic range. The HP 8530A provides a large

amount of measurement exibility, providing the features you need for many dierent types of

measurements.

The HP 8530A must be used with a frequency down converter. The following HP down

converters are supported:

HP 8511A/B frequency converter

HP 85310A distributed frequency converter

HP 85325 millimeter wave subsystems (the HP 85325A and HP 85309A, used together, make

a complete frequency converter system).

reference

and

test

MHz

the

to 20

basic

block

diagram

of

an

products down-convert

These

signals

antenna

that are

measurement

measured by

system.

microwave (or

the HP

8530A. Figure

millimeter) signals

shows

1-1

Getting Acquainted

1-2

with

the

HP

8530A

Receiver

Figure

1-1.

Basic

Antenna

Measurement

Block

Diagram

Receiver Performance

The most important feature of the HP 8530A is the accuracy and speed with which it makes

measurements. The important performance features are:

Excellent sensitivity.

.

Excellent

speed

High

linearity

over a

data acquisition

dynamic

wide

capability

range

.

Sensitivity

The foundation of good system performance

measure very small signals

. Excellent sensitivity

noise. When used with the HP 85310A frequency

and high speed is sensitivity|the ability to

is only possible in systems that have very low

converter, the HP 8530 can measure signals

of0113 dBm from 3 to 18 GHz, and096 dBm from 18 to 26.5 GHz. Excellent sensitivity

improves the signal-to-noise ratio of your system, allowing you to measure smaller signals more

quickly

,

and

with

greater

accuracy

.

Receiver

8530A

HP

Getting

Acquainted with

the

1-3

Linearity over a Wide Dynamic Range

Accuracy errors can occur when the power from the test antenna varies in signal level. For

example, assume that a test antenna has a bore-sight measurement of 0 dBi (020 dBm) and an

o-axis null of050 dBi (070 dBm). This is a dierence of 50 dB. The HP 8530A receiver has

0.03 dB of error in this case. Even with a 60 dB dierence the HP 8530A has less than 0.04 dB

of error due to linearity. This specication is called \dynamic accuracy."

Fast Measurement Speed

The HP 8530 can measure 5000 points per second. As mentioned earlier, averaging slows

measurement speed. Because of the HP 8530A's excellent performance, you will need less

averaging, and can make faster measurements, than you would when using a receiver with less

performance.

High speed measurements are performed using the \Fast CW" mode, and must be done through

computer control.

Getting Acquainted

1-4

with

the

HP

8530A

Receiver

Measurement Features

The major

operational

features of the HP 8530A are listed below:

Angle Domain

Allows you to make angle scan measurements at a single frequency. In Angle Domain mode,

the x-axis of the display is angular degrees.You can measure a single angle, or a range of

angles. If you DO NOT have an HP 85370A Position Encoder, use external triggering (HP-IB or

TTL) in this mode. If you use the HP 85370A Position Encoder, use internal triggering mode.

Domain

phase

performance

must be

Internal

.

be

can

Frequency

made

used

List

across

single

a

at

triggering

well.

as

sweep

one

angle

commonly

is

ou

Y

modes

or

.

can

.

more

Frequency

In

used

measure

a

Frequency

Allows

frequencies

Domain

when

single

you

.

mode

measuring

frequency

Domain

measure antenna

to

Frequency

the

,

Domain

x-axis

frequency

choose

or

,

display

but

of the

from Ramp

Angle

Figure

1-2.

magnitude and

measurements

frequency

is

external triggering

or

Step

,

Figure

1-3.

Frequency

Getting

Domain

Acquainted with

the

HP

8530A

Receiver

1-5

Time Domain

This optional feature allows you to make RCS measurements or see the time response of an

antenna (time is shown on the displays x-axis). One use of time domain is when measuring

multi-path range reections. Internal triggering is usually used in this mode.

Time domain data is mathematically calculated from Frequency Domain data. This is done

using the \chirp-Z" inverse Fourier transform. Therefore, the rst step in time domain

measurements is to make a measurement in the Frequency Domain.

Domain

Time

Figure

1-4.

Calibration

Antenna

calibrating

reduces

A

make

the

measurement errors

\network

network

impedance

calibration

coupler

is

calibration provides

your range

analyzer"

against

calibration

analyzer-type

antenna

an

of

make

could

you

so

measure

required

to

accurate

standard

a

caused

gain

signal

by

provided.

also

is

measurements

output).

(or

input

accurate

very

reected

the

frequency

and

antenna.

gain

crosstalk.

example

or

F

.

ou would

Y

measurements.

signals.

This

response

the

,

Also

calibration

assume you

,

perform the

In this

measurements

isolation

is used

calibration

if you

want to

network

example a

by

feature

to

want

measure

analyzer

directional

Four Measurement Inputs

The receiver has four inputs for receiving signals (a1, a2, b1 and b2). You must input a

reference signal into a1 or a2. Then, any other inputs can be used as test signal inputs.For

example

test

carry

your

for

assume you

,

signals.

The

measurement.

input

ARAM"

\P

reference

the

keys

signal

described

,

into

below

a1.

Y

select

,

ou

could

which

then

inputs to

use a2,

b1,

ratio

together

to

b2

or

Selectable Input Ratios

4

PARAM 1

measure.

,

4

5

PARAM 2

,

4

5

PARAM 3

, and

5

4

PARAM 4

(\PARAM" is short for \parameter

, select a specic pair of inputs to ratio and

5

,

or example

.") F

4

PARAM 1

5

mathematically

divides

(ratios) input b1 data by a1 data. You can redene the PARAM keys so they ratio any two

inputs you desire.You can also measure a single input without ratioing.

Getting Acquainted

1-6

with

the

HP

8530A

Receiver

Flexible Triggering

The HP 8530A provides three ways of triggering measurements:

Internal When in Internal trigger mode, the receiver does not require any

external or HP-IB triggering. This is useful when making frequency

measurements, or when using the HP 85370A Position Encoder.

External Triggering Allows you to trigger measurements using a TTL increment signal

produced by a positioner controller. This allows the receiver to take data

when the positioner is aligned with each measurement angle.

HP-IB Triggering Allows a computer to trigger a measurement by issuing a GET command

over the HP-IB bus.

Save/Recall Registers

The receiver has eight Save/Recall registers. Each can save current measurement settings for

instant recall at a later time. Register 8 is the \User Preset" register. Settings saved under

register 8 become active whenever you turn the receiver ON, or when you press

4

USER PRESET

5

.

Measure

Normalize

The

amplitude)

reference

relative

be

will

Remote

8530A

HP

The

All

.

HP-IB

modes

Data

The

of

Presentation

8530A

HP

erformance

P

function

Trace

can

ou

Y

.

dB

0

to

the

data

peak.

point.

When

to

Programming

can be

front panel

operation

controlled

features

and current

Features

show measurement

can

Relative

sets

use

then

saved,

is

remotely

are

instrument or

to

peak

the

markers

printed,

from

supported.

results right

the

of

to

plotted,

any

ou

Y

system

main

view

computer

can

on its

lobe

trace

output

or

query

status

display

(the

magnitude

to

that

the

.

Main

the

of

eak

P

the

Antenna patterns

Frequency response measurements

Time domain

Radar Cross Section (RCS) frequency and time domain measurements

8530A

HP

The

Display F

allows

ormats

you

print

to

You can select logarithmic or linear

display format (Cartesian only). Y

plot measurement

or

results

magnitude display formats (Cartesian or polar), or phase

ou can display

one,two, or four parameters simultaneously on

.

the screen.

Lobe

point

data

values

computer

communicate

can

analyzer

can

It

of

relative

magnitude

,

determine

to

display:

highest

to this

values

using

current

Multiple Measurements Can be Shown Simultaneously

The HP 8530A allows you to view up to four parameters at once, in split or overlay

independent

the

of

presentation.

measurement

Alternatively

channels

(more

,

you

on

display

can

channels

one

explained

is

parameter from

later).

Getting

Acquainted with

each

the

HP

8530A

Receiver

1-7

Trace Memory and Trace Math

The trace memory feature is similar to the storage feature in a storage oscilloscope.You can

store the current data trace to memory, then compare it to subsequent measurement traces.

Trace math features allow you to perform vector addition, subtraction, multiplication, and

division. These operations are performed using the current data trace and the memory trace.

Each parameter has independent trace memory/math operation. In addition, trace math in

Channel 1 is independent from trace math in Channel 2.

Markers Display Precise Values for Any Point on display Traces

Five measurement markers give detailed information about any point on the measurement

trace. Delta markers allow you to show the dierence in amplitude, phase, angle,ortime

between any two points on the screen.

External Video Monitor

The HP 8530A can display results on an external multisync monitor. Refer to Appendix B for

details.

Optional Network Analysis

Option

This

011

allows

frequency

accuracy

adds

you

or

in

high-performance

measure

to

optional

arameter

S-P

time

the

domains

network

vector

network

transmission

These

.

measurements

analysis

reection

and

advanced

.

features

properties

calibration

(HP

of

features

8510C

operation).

microwave

provide

devices

optimum

in

Getting Acquainted

1-8

with

the

HP

8530A

Receiver

Input/Output Features

The HP 8530A can control other instruments, and has many input/output capabilities using

HP-IB, System Bus, RS-232, external monitor interface, and TTL BNCs.

Printing and Plotting Features

The HP 8530A can output data to a wide range of HP-IB or RS-232 printers or plotters. Laser

printers are also supported.

Many Supported Peripherals

The HP 8530A can control RF and LO signal sources, frequency converters, and large external

display monitors. Refer to Appendix B for details.

Built In Disc Drive

The built in disc drive allows you to save measurement data, data from memory, instrument

conguration setups, save/recall registers, calibration data, or user-created graphics. Both

LIF

and

DOS

format

DOS

format

LIF

workstation

formats

disc

compatible

is

compatible

is

family

are

with

supported,

MS-DOS

Hewlett-P

and

R



based

ackard

computers

,

such

as

IBM

the

PCs

HP

automatically

are

types

disc

both

.

recognized.

compatibles

and

9000 Series

300

.

Getting

Acquainted with

the

HP

8530A

Receiver

1-9

Principles of Operation

This information is provided so you can have a better understanding of how the HP 8530A

makes measurements. If desired, you can skip this section and come back to it when

convenient.

Description of the HP 8530A

A simplied block diagram of the HP 8530A receiver is shown in Figure 1-5. It is a high

performance vector receiver with four inputs, two independent digital processing channels,and

an internal microcomputer that controls measurement, digital processing, and input/output

operations. Examples of \digital processing" are features such as averaging, time domain,

calibration, and so on. A special System Bus gives the receiver complete control over the

RF source and, if required, LO source. This interface allows the receiver to make hard copy

outputs to HP-IB compatible printers or plotters. Two RS-232 ports are also supplied for

printing or plotting.

The system must contain a frequency converter, which down converts the RF measurement

frequencies to a 20 MHz IF. The HP 8530A requires this frequency for its inputs.To create

the IF frequency, the HP 8511A/B frequency converter uses a built-in local oscillator. The

est

\T

the

over

is

built-in

Set

LO

Interconnect"

measurement

signal.

IF

MHz

LO

supply

the

an

System

Bus

digitally

that

signals

Other

signal.

.

tuned

links

with

down

The

the

by

HP

the

similar

a

converters

8530A

HP

8530A. This

HP

8530A

and

frequency

such

,

external

tunes

that

as

digital tuning

the HP

oset by

is

HP 85310A,

the

LO

data is

8511A/B.

The local

20 MHz.

require another

sources with

sent

oscillator mixes

The result

is the

source

HP-IB commands

to

sent

the

20

over

Getting Acquainted

1-10

with

the

HP

8530A

Receiver

Figure

1-5.

HP

8530A

Measurement

Data

Flow

Diagram

The

HP

8530

has

two

main

sections:

Analog:

In

the

main section,

rst

analog circuitry

detects

the real (x) and imaginary (y) values of the input signals. The real,imaginary values are then

converted into digital values.

Digital: In the second main section, the microprocessor takes the digital data and performs

any desired data processing (averaging, calibration, time domain, and so on). The instrument

results

disc

,

and

or

the

external

Channel

displays

then

plotter,

Channel 1

view the dierent results

results

output

then

can

ou

Y

two

.

identical

features

digital

turned

processing paths

ON

choose

There

.

have

you

are

dierent

any format

in

computer

can

ou

Y

2.

ou can show the results of both channels on the screen at the same

.Y

the

in the

two

to printer

called

,

channels

,

and

time.

Receiver

8530A

HP

Getting

Acquainted with

the

,

1-11

Analog Signal Process Stages

During a typical Frequency Domain measurement, the test signal source is swept from a lower

to a higher frequency.

During a typical Angle Domain measurement, a single frequency can be measured while the

antenna-under-test is moved around one axis.

Initially, the HP 8530A receives up to four 20 MHz signals from the external frequency

converter. The receiver separately down converts each signal to a 100 kHz IF carrier frequency

that can be used by the detection circuitry. Because frequency conversions are phase coherent,

and the IF signal paths are carefully matched, magnitude and phase relationships between

the input signals are maintained throughout the frequency conversion and detection stages.

Automatic, fully-calibrated autoranging IF gain stages maintain the IF signal at optimum levels

for detection over a wide dynamic range.

Each measurement channel can use input a1 or a2 as the reference signal. The selected input

is also used as the phase-lock reference.

Note

Any

of

the

In hardware gating applications, the pulsed reference signal may not be suitable

for phase locking. In this case, you can use the other reference input for phase

you

a1,

input

on

press

,

is

RESPONSE

three

locking. F

the phase

a2 as

NN

N

NN

REDEFINE

remaining

example

or

lock

N

NN

N

PARAMETERS

inputs

N

can

assume

,

reference

N

NN

N

NN

N

PHASE

used

be

N

NN

your

.

N

as

pulsed

accomplish

o

T

N

NN

N

LOCK

test

reference

NN

N

.

a2

inputs

this

.

4

MENU

can

use

5

input

The

these

When

Getting Acquainted

1-12

selector

measured

are

sends

with

one

the

Figure

test

input

8530A

HP

signal

selector

1-6.

and

Receiver

Phase

reference

one

sends the

Lock

Reference

signal

test/reference

other

to

synchronous

the

signals

detectors

.

The synchronous detectors develop the real (x) and imaginary (y) parts of the test or

reference signal by comparing the input to an internally-generated 100 kHz sine wave. This

method practically eliminates drift, osets, and circularity errors as sources of measurement

uncertainty. Each x,y pair is sequentially converted to digital values which are sent to the

main microprocessor.

Digital Data Process Stages

Digital signal processing proceeds under the control of the receiver's rmware operating system

executed by the main microprocessor.

About the Main Microprocessor

The main microprocessor is a 32-bit Motorola 68020 microprocessor running at a clock speed of

16 MHz. The rmware operating system takes advantage of multi-tasking software architecture

and several distributed processors to provide very fast data acquisition and display update

speed.

Raw Data Stages

The microprocessor accepts the digitized real and imaginary data, and corrects IF gain and

quadrature

correction

IF

the

in

automatic

by

way

any

errors

feature

the

before

is

user

any

are

stage

dierent

.

data

other

calculated

the

from

processing

is done

periodically with

calibration

user

. The

an automatic

features

,and

calibration coecients

self-calibration. This

cannot be

controlled

used

in

independent

to

sent

are

data

the

F

1

is

orm

of

Channel

or

channel

raw

1

.

one

holds

described

if

format.

1

data

you

.

X,Y

in

are

2.

ast CW

F

If

array

data

the

using

the

If

Similarly

.

HP

pair

the

ast

F

mode

in

8530A

F

mode

CW

is

Channel

,

special

a

eyword

K

CW

ast

not

is

being

mode

inputs

the

Next,

Channel

and

any

,

use

Channel

\arrays"

1

selected

data

sent

is

1

is stored

are data

Channel

Now

in

used,

averaged

Data

compressed data

Dictionary

buer

The

The F

.

contains up

ratioed

are

data

2

averaging

ast

F

the

to

averaged

data

in the

holding locations

format called

ast CW

buer can

to 100,000

together

processing

performed

is

buer

CW

stored

is

Channel

\Form

X,Y data

identical

and

paths

on

from

in

raw

2

A

.

1." This

data

send

Channel

the

data

pairs

copies

.

active

the

Channel

array

format

computer

to

in

Other Digital Processing Stages

Channel 1 and 2 data processing proceeds independently through subsequent data processing

steps. Dierent measurement features can be used in each channel, causing the measurement

shown

be

results

to

Processing"

on. F

so

and

Domain

in Channel 1. This allows you to make two dierent types of measurements on the

same device

processed

steps

example

or

, and display the results simultaneously

and

shown in

you

,

Figure

can

More information on the \other"

Operation," later in this guide

.

\Other

the

Time

and select

2,

are

Domain,

in dierent

and

,

1-5

Time

select

ways

include

Domain

features

These

.

calibration,

Channel

in

.

data processing steps is provided in \Standard A

Data

display

format,

Frequency

utomated

2

.

Getting

Acquainted with

the

HP

8530A

Receiver

1-13

Front Panel Overview

This section describes the receiver's display and the purpose of the major control blocks. Note

that you can press any key, at any time, and in any sequence without fear of damaging the

system.

Display

Figure 1-7.

The display shows measurement results and softkey menus. It also shows you the current

measurement settings.Various types of screen messages always show up in the same areas on

the display. Figure 1-7 shows the areas in which specic types of messages appear.

8530A.

HP

the

read

you

As

Getting Acquainted

1-14

this

section

with

press

the

described keys

the

8530A

HP

Receiver

on

Front Panel Overview

Channel Selection

The receiver has two separate, identical measurement channels. The channel feature is much

like having two HP 8530 receivers setting next to one another.

Channel 1 and 2 can have dierent PARAMETER, FORMAT, or RESPONSE settings,in

addition, you can select Time Domain on one channel, and Frequency Domain on the other:

For example, you could set Channel 1 to Frequency Domain, PARAM 1. Then you could set

display

and

both

sets

Time

to

Channel

data. Y

2

ou can

view the

data side-by-side

Domain,

P

data separately

(dual channel

ARAM

split) or

receiver

The

2.

changing

(by

superimposed (dual

measure

will

channel),

channel

or

each

can

you

overlay).

channel

the

of

\stimulus"

Many

frequency

cannot

you

\uncoupled,"

is

whether

a

number

,

choose

specic

settings (such

points

of

dierent

choose

can

you

feature

is

as RF

and

,

settings

dierent

coupled

so

power;

are

on)

Channel

for

settings

uncoupled,

or

,

stop

start,

\coupled." If

versus

1

the

in

look

increment

a stimulus

Channel

channels

two

in

up

it

angle;

start,

feature

a stimulus

If

2.

If you

.

the keyword

,

stop

\coupled,"

is

feature

to

want

dictionary

CW

or

know

.

Getting

Acquainted with

the

HP

8530A

Receiver

1-15

Front Panel Overview

Basic Measurement Functions

Four of the main control blocks on the front panel are STIMULUS, PARAMETER, FORMAT,and

RESPONSE.

These

STIMULUS This

settings

of

into

selecting

the

described

are

block

data.

the

GET

It

.

or

F

receiver's

EXTERNAL

command.

below:

you

lets

controls how

also

example,

select

you can

EVENT

trigger

RF

power

levels

you can

trigger

TRIGGER jack

Alternatively

.

,

trigger

the

o

from the

,

desired

and

the

Record

you can

frequency

instrument

Increment

positioner

trigger

and

take

to

pulses

controller)

HP-IB

over

angle

each

(coming

using

point

by

4

keys

ratio

and

Ratioed

the

of

any

at

input

4

P

ARAM

5

4

ratio

measurements

actual

performance

parameter

single

.

(b1/a1).

(divide)

keys

input

ARAM

P

The

reduce

to

using

the

of

ratio

the

ARAMETER

P

ARAMETER

P

The

(b1/a1),

4

ARAM

P

measurement

the

from

data

errors

most

Antenna

any

N

SERVICE

Under

two inputs

N

NN

N

1

N

2

mode

test

caused

T

you

N

NN

N

through

a1

block

(b1/a2),

5

for

and

by

est.

desire

contains

4

ARAM

P

receiver

the

reference

range

the

can

ou

Y

.

N

SERVICE

,

redene

can

ou

N

NN

N

predened

the

(b2/a1),

5

3

to

is

antennas

shows

and

any

also

NN

N

b1

4

mathematically

.

look

N

softkeys

FORMAT Format keys let you choose how the data is displayed on the screen. You

can select logarithmic magnitude (

RESPONSE

phase (

magnitude (

The

Functions

(Normalization

measure other

4

5

PHASE

), polar logarithmic magnitude (

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

LINEAR ON POLAR

response block

under

the MENU

allows you to set the peak of the main lobe to 0 dBi and

parts of the trace relative to the peak.)

keys

let

Each major control block has functions that are not mentioned here

and 9 in the

HP 8530A Operating and Programming Manual

Many features are described in this User's Guide

4

LOG MAG

5

), linear magnitude (

4

POLAR MAG

5

), and polar linear

4

, located under the FORMAT MENU key)

reference

and

averaging

on

scale

normalization.

and

you

key

to

let

set

you

the

turn

display

. Refer to Chapter 6, 7, 8,

for descriptions of these features

.

LIN MAG

line.

5

1

normal

the

5

),

.

Getting Acquainted

1-16

with

the

HP

8530A

Receiver

ENTRY Block

Front Panel Overview

cases

some

In

frequency

digits

4

k/m

entering

to

the

.

terminate

(kilo/milli)

5

and

8

Changing

it

The

data

keys

9

Values

necessary

is

keypad

digit

10

value

the

4

and

with

x1

the

(basic

5

allow values

Using the

supply

to

used

is

appropriate

the

with

units:

keypad, the

to be

Numeric

numeric

supply

to

dBm,

,

dB

knob can

changed

values

units

degrees

be

steps

in

eypad

K

these

.

used

.

a

for

values

Use

seconds

,

to

specic

The

.

4

(Giga/nano),

5

G/n

,

make

function,

keys

applicable

as

Hz)

continuous

such

the

to

4



M/

adjustments

the

of

right

(Mega/micro),

5

addition

In

.

,

while

or

angle

as

To change a value using the numeric keypad:

1. Select the function (start angle, frequency, or any other function that requires a value). This

function becomes the \active function."

4

the

entire

and

4

CKSP

BA

value).

.

4

5

0

+/

(If you

.

key

5

CE

A

+/

5

0

have

changes

already

.

toggle

the

pressed

sign of

Enter

2.

number

the

terminator

a

erminate the

3. T

new value

the

decimal,

,

press

,

the

If you

.

key

make

, you

using

must

numeric

mistake

a

re-enter

entry with the appropriate units

Getting

Acquainted with

the

HP

8530A

Receiver

1-17

Front Panel Overview

Table 1-1. Numeric Value Terminator Key Usage

Key

Angle Frequency Power Power Slope Time

Name

G/n { GHz { { ns

M/



{ MHz { {



s

k/m milli degrees kHz { { ms

1

x1

4x15

degrees Hz dBm dB/Ghz s

always represents single units.

Other Keys in the Entry Block

4

PRIOR MENU

4

=MARKER

4

=MARKER

5

takes you to the previous softkey menu.

5

can be useful when you are using markers. The easiest way to explain what

5

does is by example. Assume you are making a frequency response measurement,

and the last marker you moved (the active marker) is sitting at 11 GHz. Now assume you want

to change the start frequency to 11 GHz. All you need to do is press

4

START54=MARKER

5

.The

marker position (11 GHz) will become the start frequency.

value

line

4

STOP

to another

the

to

4

V

REF

marker

5

value

ALUE

.

4

=MARKER

function.

of

4

5

=MARKER

the

.

5

active

5

,

As

and

an

marker

the

could

ou

Y

Another

example

(for

display

have

way to

assume

,

assume the

,

reference

the

set

use

4

=MARKER

you want

line

frequency

stop

5

to set

marker value

change

will

transfer the

is to

the

to the

11

to

display

0

is

value

GHz

marker

reference

dB).

13.2

of

pressing

by

the

Press

active

4

ENTRY

OFF

function

function.

removes

5

text"

are

error

old

messages

START

like

or

0

active



90

that

function

appear

text

when

from

you

screen.

the

changed

the

ctive

\A

value

of

a

Getting Acquainted

1-18

with

the

HP

8530A

Receiver

MENUS Block

Front Panel Overview

The four keys under MENUS are

CAL Softkeys under

4

5,4

CAL

DOMAIN

4

5

allow you to perform an antenna, radar cross section

CAL

5,4

DISPLAY

5

, and

4

MARKER

5

:

(RCS) or limited network analyzer calibration.

DOMAIN The HP 8530 has three modes of operation, called domains. These are the

Frequency, Angle, and optional Time Domain.

DISPLAY Softkeys under

4

DISPLAY

5

:

Place one, two, or four parameter measurements on the screen at once.

are:

memory.

colors

an

for

traces.

.

external

to

up

desired

a

monitor

markers

ve

point

on

.

Each

.

the

MARKER

the data

Saves

Displays

erforms trace

P

Allows

Softkeys

marker

memory traces

you

under

shows

measurement

Simple

4

Marker

markers

marker

search

list

trace to

math functions

change display

to

choose video

to

4

MARKER

amplitude

Marker

.

trace

the

on

.

mode

modes

.

modes

temporary storage

.

on memory

intensity or

settings for

to

you

allow

5

or

phase

values

Functions

display

trace

.

activate

.

Getting

Acquainted with

the

HP

8530A

Receiver

1-19

Front Panel Overview

INSTRUMENT STATE Block

The four keys in the INSTRUMENT STATE block are

The

4

5

LOCAL

key has two uses:

4

LOCAL

5,4

SAVE

5,4

RECALL

5

, and

4

USER PRESET

If you are controlling the receiver with a computer, the front panel keys will not respond to

touch. Pressing

4

5

LOCAL

also allows you to examine or change HP-IB addresses the receiver uses to control

4

LOCAL

5

returns control to you.

peripherals and other instruments.

4

5

and

SAVE

4

RECALL

5

allow you to save and recall up to eight dierent measurement setups

(\instrument states"). You can also save your current setup as the \USER PRESET" state by

turned

saving

or

on,

state

A

stimulus

register

to

it

you

if

dened

is

parameter

,

press

8.

4

USER

the

as

format,

,

receiver

The

PRESET

condition

5

and

will

.

all

of

response

return

current

settings

state

that

to

measurement

.

whenever

settings

instrument

the

including

,

is

all domain,

5

.

Getting Acquainted

1-20

with

the

HP

8530A

Receiver

AUXILIARY MENUS Block

Front Panel Overview

The \AUXILIARY MENUS" contain the

4

5

COPY

4

DISC

controls hardcopy output, either printing or plotting.

5

controls saving, loading, viewing, or deleting disc les.You can also format oppy discs,

4

COPY

5,4

DISC

5

, and

4

SYSTEM

5

keys.

or select an external disc drive.

4

SYSTEM

5

menus control internal functions of the HP 8530. For example, you can select normal

or wide IF bandwidth, or control phase locking.

If using remote mixers, you can control the RF-to-LO frequency ratio (to select the desired

harmonic mode) using the Multiple-Source menu.

Getting

Acquainted with

the

HP

8530A

Receiver

1-21

Front Panel Overview

Automatic Recall of Instrument Settings

The receiver

between

forth

remembers

settings

Save

the

instrument

feature

This

Channel

Domain

arameter

P

Format

Response (scale

Every

mode

automatically

channels

the

all

or

stimulus

Recall

except

state

works

or

(1

(Frequency

(1,

display

(any

the

in

remembers most measurement settings. When you switch back and

domains

,

lower-level settings

settings.)

This

functions

memory

by

.

."

assigning

2)

or

,

Angle

,

4)

or

3,

2,

format)

reference

and

above list

remembers

parameters

,

you used

This feature

ability

hierarchy

a

Time)

line)

or

,

last. (This

is automatic

remember

to

the

to

settings you

all

display

make that

the

formats

,

feature remembers

does

,and

settings

For example, assume you choose the following measurement settings.

Channel 1

Angle Domain

Parameter 3

Log mag (format)

dB

10

dB/div

5

0

Reference

Scale

receiver

not

Here

.

lower

are

automatically

measurement

all

require

called \limited

is

you

the

is

the

in

use

to

hierarchy:

hierarchy

.

Now you go to Channel 2 and make completely dierent settings

When you reactivate Channel 1, the settings shown above will automatically

.

resume. This

hierarchical memory applies to all the controls in the above list.

The Added Benet of the SAVE/RECALL feature

Stimulus settings are not part of the hierarchical memory explained above.To save stimulus

Another

settings

along

advantage

Getting Acquainted

1-22

with all

that saved

is

other

the

instrument

the

with

HP

settings

8530A

,

states

Receiver

you

can

must

be

use

stored

the

to

SA

disc

VE/RECALL

.

feature

.

Typical Softkey Menu Structure

Front Panel Overview

Each

the

on

Every

choices

the

of

menu

side

softkey

.

function

contains

the

of

when

,

blocks

up

display

pressed,

to

.

contain

eight

Press

either

4

a

MENU

selections

softkey

the

activates

,

that

key

5

corresponding

each

the

to

function,

the

presents

right of

the

or

softkey

one

to

function

presents

menus

of the

you

the

on

unlabeled

to

want

level

keys

select.

menu

of

Getting

Acquainted with

the

HP

8530A

Receiver

1-23

2

Manual Measurement Examples

This chapter gives basic examples of antenna and RCS measurements. The intent is to show

you the overall steps involved in making a measurement, but not to go into great depth on

measurement choices. This chapter also explains simple (but very useful) tasks such as using

markers, nding depth of a null, determining beam width, and displaying more than one

parameter.

After you become familiar with the concepts presented in this chapter, you can read Chapter 4

to learn more advanced measurement skills.

Chapter

Denitions

Antenna

Angle

Frequency

Measurements

RCS

Frequency

domain

Time

Angle

CW

Contents

Important

of

Measurements

measurements

scan

response

measurements

Scan

erms

T

measurements

Measurement Examples

Manual

2-1

Angle Scan Measurements

Denitions of Important Terms

It is important that you understand the denition of the following terms

HP 8530A

Channel

Input

Ratio

arameter

P

.

The receiver has two separate, identical measurement

feature is like having two HP 8530 receivers setting next to one another.

When the receiver measures raw data, it makes two identical copies. Each

copy is sent through parallel (identical) data processing paths. Such features

as calibration, Time Domain, display formatting, and trace math can be

performed on one or both paths. Each of the two channels correspond to

one of the data processing paths (refer to Figure 1-5). When you press the

4

CHANNEL 1

Any subsequent changes you make to measurement settings will aect that

channel.

Refers to the four HP 8530A signal inputs (a1, a2, b1, and b2). The term

\input" is also used when referring to the signal inputs of the frequency

converter (HP 8511A/B, 85310A, or other.)

Most often, users want to divide the measured signal of the

signal

or example

(F

reference

rejection

The

measurement.

4

ARAM

P

b2/a1,

a1.

desire

N

SERVICE

N

NN

SERVICE

5or4

of the

signal at

errors

of

parameter

are

5

4

so

and

can

ou

Y

view

o

T

.

N

NN

N

3

N

NN

N

PARAMETERS

CHANNEL 2

reference

, selecting

a1.) A

caused

the

is

front

The

the

at

set

or

F

on).

redene

single

a

N

a2

N

,

SERVICE

N

NN

N

5

key, you make that channel the \active channel."

or

,

input.

input,

example

the

N

.

This is

b1/a1 would

ratioed measurement

transmitter

the

by

input

or

keys

panel

select

ARAM

N

b1

4

N

to

,

use

N

4

P

ARAM

keys

the

softkeys

factory

P

input,

NN

called a

divide the

ratio

4

ARAM

P

so

N

ratio

transmit

,

that you

,

5

1

dierent

divides

5

1

they

N

NN

N

SERVICE

located

,

signal

test

provides common-mode

have selected

4

ARAM

P

input

(ratios)

any

ratio

N

1

under

N

a1

NN

N

,

as they relate to the

channels

ratioed,

antenna,

,

5

2

ratios

two

N

SERVICE

P

. The channel

test

input by the

measurement.

the

by

b1

at

drift.

or

for

4

ARAM

P

input

NN

N

ARAMETER

3

(b1/a1,

b1

inputs

N

,

5

by

you

N

2

and

N

b2

a

NN

N

,

4

MENU

5

Manual Measurement

2-2

Examples

Angle Scan Measurements

Antenna Measurements

The rst part of this chapter describes the two supported types of antenna measurements:

Angle Scan The HP 8530A can make single-axis angle scan measurements at a

single frequency.You can measure a single angle, or an angle sweep.

Frequency Response This is a measurement at a single angle over a range of frequencies.

When selecting frequencies, you can:

Specify a list of specic frequencies.

Select the start and stop frequencies, and the number of points. The

receiver will pick the individual frequency points in-between.

Note

When this

give the

refers

to

Softkeys

Select a frequency center point, a frequency

span

, and the number

of points. The receiver will pick the individual frequency points

throughout the span. This method is useful when you want to look

closely at a smaller portion of the frequency band.

In frequency measurements, triggering should usually be set to

internal triggering.

4

four

the

manual instructs

name of

the

are

the functional

4

MENU

shown

key

5

N

LIKE

N

you to

located

NN

N

THIS

block rst.

in

N

.

press one

the

of

example

or

F

STIMULUS

MENU

STIMULUS

,

functional

5

keys

block.

,it

4

MENU

will

5

Measurement Examples

Manual

2-3

Angle Scan Measurements

This tutorial will show you how to make a typical angle scan (pattern) measurement.

Notes Regarding Angle Scan Measurements

The HP 8530 does not send commands to the positioner controller.You must set the start, stop,

and increment angles on the positioner controller directly. The only exception to this is if your

positioner controller is completely manual. To make the measurement, use the positioner

controls to rotate the antenna.

What Triggers Measurements at Each Angle?

On systems NOT equipped with the HP 85370A Position Encoder:

The receiver, using External

Trigger, measures one data point every time a Record Increment trigger is sent by the

positioner controller. The receiver uses the Record Increment trigger to:

Know when the antenna is at an angle where a data point is to be taken.

Keep track of how many angular data points have been measured, and thus, when the

measurement is nished.

ARE

On

systems

that

Encoder automatically

positioner

the

time

each

taken).

Receivers

explained

Example

example

The

in

Measurement

that

\External

measurement

Display:

arameter:

Measured

Start

Stop

Increment

P

Angle:

equipped

knows

the

reaches

the

use

Triggering"

will

Single

aram

P



90

0



+90



1

with

selected

increment

an

position

in

the

use

(b1/a1)

1

HP

the

encoder

Chapter

following

85370A

increment

angle

use

4.

settings:

osition

P

angle

(an

internal

Encoder:

causes

It

.

where

triggering.

a

The

the

data

More

HP 85370A

receiver

point

this

on

to

is

Frequency: 10 GHz (X-band)

Position

trigger

be

to

subject

is

Manual Measurement

2-4

Examples

Angle Scan Measurements

Setup

Typical

Figure

2-1

est

T

shows

Setup

typical

a

Figure

antenna

Typical

2-1.

measurement

Antenna

setup

Measurement

.

You must not connect a signal to the Event Trigger BNC if your system uses the HP 85370A

Position Encoder.

Connections to Event Trigger could cause false triggers to the Position

Encoder.

Calibrate

to

reduce

or

measurements

calibrated

make

to

want

you

If

gain

,

crosstalk

errors,

refer

Chapter 3.

Make

1.

2.

3. Determine

Measurement Settings

Press

4

RECALL

5

NNNNNNN

MORE

NNNNNNNNNNNNNNNNNNNNNNNNN

NNNNNNN

FACTORY PRESET

NNNNNNNNNNNN

Select angle measurements by pressing

STIMULUS

keys

entry

appropriate

an

4

MENU

example

for

,

N

5

POWER

power

RF

N

NN

N

MENU

4

5

-

1

N

,

5

0

level

N

POWER

4

would

5

x1

.

4

NN

N

DOMAIN

for

N

SOURCE

select

5

your

N

NNNNNNNNNNNNNNNNN

ANGLE

setup

N

NN

N

Then

.

1

10

0

.

dBm.

Change

enter

the

power

RF

desired

pressing

by

value

using

the

Measurement Examples

Manual

2-5

Angle Scan Measurements

4. Select angle and frequency settings by pressing the following keys:

4

5090

START

4

5904x15

STOP

STIMULUS

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

FREQUENCY of MEAS.

4x15

4

MENU

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

5

,

INCREMENT ANGLE14x15

10

4

5

G/n

4

PARAM 1

5. Set the receiver for the correct triggering mode:

Press:

a. If your systemisequipped with the HP 85370A Position Encoder,press

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TRIG SRC: INTERNAL

b. If your system

increment triggering directly front the positioner controller, press

6.

Press

erform the

7. P

a.

Press

b.

If

c.

If

d.

If

e.

If

the

On

8.

5

NNNNNNNNNNNNNN

MORE

4

PRIOR

4

PRIOR

A

Axis

A

Axis

prefer

you

prefer 0

you

positioner

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TRIGGER MODE

.

is not

5

MENU

following sub-steps

MENU

your

on

your

on

6

controller:

equipped with the HP 85370A Position Encoder, and gets its record

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

CONTINUAL

NN

N

5

ENCODER

positioner



180

display



to 360

display

.

only

N

FUNCTIONS

a

uses

a

uses

press:

,

press:

,

you

if

N

NN

N

single

dual

NN

N

+/-180

NN

have

N

AXIS

synchro

N

ANG

N

POL

N

the

N

NN

N

A

,

press:

,

N

NN

N

0to

HP

N

MORE

press:

N

85370A

N

.

N

SYNCHRO

N

DUAL

NN

N

360

osition

P

N

NN

N

NNNNNNNNNNNNNNNNNNNNNNNNNN

EXTERNAL

Encoder:

N

NN

N

SINGLE

.

N

Select manual

a.

b. Some positioner controllers can be \manually programmed" from the front panel

for a semi0automatic measurement. Such units may require you to enter a start,

stop, and increment angle. If you have a controller of this type, enter start, stop,

and increment angle values now. Use the same values you entered into the receiver.

Refer to the instruction manual for the positioner controller if necessary. If you use a

completely-manual

Set the

c.

Note

Manual Measurement

2-6

positioner

(local)

Some positioner controllers express angles from 0 to 360 degrees

than0180 to +180 degrees

positioner to the

set the positioner to 270. This is not a problem if you have the HP 85370A

Position Encoder.

operation.

positioner controller

Axis

controller

Examples

to

equivalent

.

step

this

skip

A.

. If you have a 0 to 360 degree controller

0

start angle

or example

.F

, to get

90

, rather

,setthe



you would

Angle Scan Measurements

Choose Display Format

The next step is to choose the way you want data to be displayed. The keys and softkeys in

the FORMAT block control the display format. Choose one of the following:

4

LOG MAG

4

LIN MAG

4

PHASE

4

POLAR MAG

FORMAT

Note that in Angle Domain, 0 degrees is at the top of the display in polar formats. Refer to

4

POLAR MAG

5

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

4

5

MENU

LINEAR on POLAR

displays logarithmic magnitude in Cartesian format.

displays linear magnitude in Cartesian format.

displays phase in Cartesian format.

displays logarithmic magnitude versus angle.

displays linear magnitude versus angle.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

5

and

LINEAR on POLAR

in the

HP 8530A Keyword Dictionary

for details.

Choose Display Scale and Reference Line Settings

One step 40 dB or 60 dB patterns

step:

one

N

PATTERN

in

N

When

and

N

NN

minimum

N

.

making

done

is

measurement

a

can

levels

readjust

power

you

.

for

Then

display

the

you

set

can

ou

Y

RESPONSE

Press

Individual

4

SCALE

rst

can

scale

sets

5

,

time

choose

suit

to

you

display up

the

scale

vertical

the

should

values

actual data.

the

N

NN

N

MENU

reference

and

graticule

estimate

display scale

for

N

40

NN

N

for 40

N

NN

dB

dB or

NN

N

PATTERN

controls

scale

(roughly)

After

.

60 dB

N

NN

or

dB/division.

in

the

patterns

NN

N

dB

60

maximum

measurement

Press

display

The

specify

Press

4

SCALE

.

4

REF

5

the

to

has

Change

ALUE

V

4

5

4

bottom.

a

the

5

If you had pressed

selects

This

.

5

x1

reference line

the

of

value

4

10

0

x1

.

5

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

40 dB PATTERN

4 dB/division,

. This

line

reference

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

or

60 dB PATTERN

which

represents

0

to

line

provides

specic

a

dB as

10

, the reference line is now at the top of

40

power

follows:

level,

from

dB

the display.You can place the reference line anywhere you wish by pressing:

4

REF POSN

5n4x15

, wherenis a number from 0 (bottom of the display) to 10 (top).

the

which

top

of

you

the

can

Measurement Examples

Manual

2-7

Angle Scan Measurements

Measure the Antenna

To measure the antenna under test:

NNNNNNNNNNNNNNNNNNNNNNN

1. Press MEASUREMENT

RESTART

. This step ensures that the measurement starts at the

beginning of the angle scan. Press this key before making every angle scan measurement.

Hint

This note applies to systems that are NOT equipped with the HP 85370A

Position Encoder.

Sometimes positioner controllers \skip" a trigger pulse during the

measurement. If this happens, the measurement will stop near the end of the

scan, waiting for the nal trigger pulse (or pulses). If you try to make another

angle scan, the receiver will measure the \missing" points and then stop taking

data. MEASUREMENT

4

RESTART

5

forces the receiver to abandon the previous

measurement, and starts the next scan properly (at the start angle). This is

never a problem if you are using the HP 85370A Position Encoder.

2. Using the positioner controller front panel controls, move the antenna to the start angle.

You should always move the positioner about 3in front of the start angle. When the

this

receiver displays

example the

the

Move

3.

positioner

Results

for

start angle

antenna

.

turns

example

an

MOVE

from

POSITIONER



90

0

is

0

antenna

90

,so



+90

to

are



.

The

FORWARD

positioner

receiver

ANGLE

move the

shown below:

you

will

have

about

to

measure

gone

enough.

far



93

0

.

antenna pattern

the

In

as the

Manual Measurement

2-8

Figure 2-2. Example Antenna Measurement

Examples

Results

Aborting a Measurement

Angle Scan Measurements

The MEASUREMENT

start over. When you are in Frequency Domain you can press this key whenever you want.

However, you should be careful when pressing this key in the ANGLE domain. Always follow

this procedure:

1. Stop the positioner controller and prepare it for a new scan.

2. Press

4

RESTART

start of the next scan.

4

RESTART

5

. This will abort the current measurement and return the HP 8530A to the

5

key tells the receiver to abort the current measurement and

Move it back to the start angle.

Measurement Examples

Manual

2-9

Frequency Response Measurements

Frequency Response Measurements (at a Fixed Angle)

This tutorial will show you how to make a typical frequency response measurement. The

example measurement will use the following settings:

Measured Parameter: Param 1 (b1/a1)

Start Frequency: 8.2 GHz

Stop Frequency: 12.4 GHz

Number of Frequency Points: 201

Angle: 0

Calibrate

If you want to make calibrated gain measurements, or reduce crosstalk errors, refer to

Chapter 3.

Choose Measurement Settings

1.

Select Frequency Domain measurements: Press

2.

Set the

frequency sweep



to Step

mode:

Press

4

DOMAIN

STIMULUS

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

5

FREQUENCY

4

5

MENU

N

STEP

.

N

.

faster

is

N

NN

N

system

source

RF

N

NN

5

MORE

4

MENU

5

8.2

5

12.4

mode

receiver

and

than

Ramp

the

to

N

NN

N

CONTINUAL

an

has

to

mode

ast

\F

in

compatible

is

N

4

G/n

4

G/n

4

MENU

NN

of

N

SYSTEM PHASELOCK

NNNNNNNNNNNNNN

5

MORE

points

5

NNNNNNNNNNNNNNNNNNNNNNNNN

5

NUMBER of POINTS

NOTE:

the

frequency-accuracy

point.

3.

Press

If

4.

phase

836xx

If

4

SYSTEM

5. Make sure triggering is set to internal by pressing:

STIMULUS

With internal triggering turned ON, the receiver will not wait for outside trigger pulses

before measuring data points. Instead, it will measure each point at the fastest possible

speed.

Select

6.

Ramp

source

RF

Refer

N

MORE

your

locking

sources

your

number

4

START

4

STOP

STIMULUS

than

This

.

mode

Ramp

Sweep

N

.

and a

8511

HP

Step

up

speed

measurement

turn

,

N

NN

N

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TRIGGER MODE

frequency

and

NNNNNNNNNNNNNNNNNNNNNNNNN

possible in

not

is

because

,

description

compatible

measurements

speed

Quick Step

NN

N

NN

STEP TYPE:

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TRIG SRC INTERNAL

settings

NNNNNNNNNNN

201

and

N

in

NN

N

Step

Chapter

HP

Quick Step

mode ON

N

NN

by

requires two

,but

step

BNC cable

many ranges

phase

mode

for

4

836xx

. Refer

N

QUICK

pressing the

source

to

mode"

by

NN

N

interconnections between

has

mode

Step

.

locks at

more information.

,

list

the

in

pressing:

following

each frequency

can

you

compatible

of

Appendix

keys:

use

Quick

B.

better

Step

HP

Note

7.

2-10

Select

the

Manual Measurement

When you select dierent frequency values for your measurement, HP 836xx

RF sources use the rst sweep to accurately phase lock the RF frequencies.If

application

your

actual

the

parameter

measurement.

want

you

Examples

demands

view

to

measurement

high

example

for

,

press

,

speed,

4

ARAM

P

subsequent

use

.

5

1

sweeps

for

Frequency Response Measurements

8. Determine an appropriate RF power level for your setup.

To change RF power, press:

STIMULUS

4

MENU

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

5

POWER MENU

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

,

POWER SOURCE 1

. Then enter the desired value.

9. Set the positioner controller so the antenna is at the desired angle.

Choose Display and Reference Settings

Choose a data presentation format, scale, and reference value/position as explained in \Angle

Scan Measurements". The two polar display keys,

dierently in Frequency Domain than they do in Angle Domain. Refer to

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

LINEAR on POLAR

in the

HP 8530A Keyword Dictionary

4

POLAR MAG

for details.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

5

and

LINEAR on POLAR

4

POLAR MAG

, operate

5

and

Choose Sweep Type

The receiver will already be measuring data. By default, the receiver will measure the

frequency band repeatedly.You can save data to a disc at any time, refer to Chapter 6 for

instructions.

time:

a

N

NN

N

SINGLE

N

is not

Mode

at

N

NN

N

.

The

softkey

making

receiver is

the

Y

for

STIMULUS

receiver

measurement

the

when

measurements

in

Measurements

our

4

5

MENU

will

Hold

are:

take

The

.

mode

one

letter

.

sweep

nished.

is

H

,

will

then

This

appear

stop

means

.

on

The

the

If you

Press

receiver

left-hand

want

STIMULUS

will

in

is

side

Choosing

dierent

The

oint

Single

Ramp

P

Sweep

Step Sweep

Frequency List

measure

to

underline

Hold

of

Best

the

sweep

mode

4

MENU

mode

the

mode

one

N

5

MORE

the

,and

display

Sweep

modes

sweep

NN

N

HOLD

when

under

These modes are explained in \Frequency Domain Measurement Tutorial" in Chapter 4.

Choosing Single or Continual Measurements

You can also choose between single or continual measurements, using STIMULUS

NNNNNNNNNNNNNNNNNNNN

SINGLE

N

NN

N

SINGLE

NNNNNNNNNNNNNNNNNNNNNNN

NNNNNN

CONTINUAL

or

N

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

CONTINUAL

makes

switches to Hold mode

.

single measurement.

a

, and the letter

repeats the measurement continuously

When

measurement

the

H

appears on the display

.

Manual

done

is

Measurement Examples

the

.

4

MENU

receiver

NNNNNNNNNNNNNN

5

MORE

:

2-11

Manual RCS Measurements

Radar Cross Section Measurements

This section describes how to make manual Radar Cross Section (RCS) measurements. The

HP 8530A can be used to perform these basic RCS measurements directly, using only the front

panel controls:

Frequency Domain This measurement domain will determine the reection from

a stationary target versus frequency.You can measure the

reection over a frequency sweep, at a CW frequency,or a

specic list of frequencies.

Time Domain Time domain (optional) can be used to measure the reections

of the target over time, giving the down range RCS response.

The HP 8530A will rst measure in the Frequency Domain

and then compute the Time Domain response using an inverse

Fourier Transform.

Software Gating Time domain gating can be used to remove unwanted

RCS responses in both time and Frequency Domain RCS

measurements. The gating function can \lter out" various RCS

error signals such as feed coupling, monostatic antenna return

.

made

frequency

target

the

This

.

to

,

up

pattern

the

than

showing

This

.

trigger

and

measurement

domain

angle

an

except

receive

antenna.

RCS

is

the

of

done

a

is

Angular

CW Measurements

, chamber

loss

An angle

target

by

the

similar

domain measurement

versus

positioner

a

using

receiver

concept,

in

measurement

positioner

moves

reections and

rotation

angle

system

measurement

each

at

hardware

and

antenna

an

of

target,

the

range clutter

can be

CW

a

at

move

to

angle

set

radiation

rather

the

Since

following

tutorials

following

The

antenna

section

this

In

Domain

Time

tutorial

builds

starts

upon

procedures

measurement

will use

we

response

Frequency

a

with

assume

also

section earlier

some of

calculated

is

example

that

in this

the skills

from

Domain

.

have

you

chapter.

and

Frequency

the

measurement.

RCS

and

read

procedures

Domain

become

discussed

measurement,

of

Each

familiar

.

earlier

the

with

the

following

the

Manual Measurement

2-12

Examples

Manual RCS Measurements

Frequency Domain Measurements

The following tutorial will show you how to make a typical Frequency Domain RCS

measurement. The example measurement will use the following settings:

Measurement Parameter: Param 1 (b1/a1)

Start Frequency: 8.2 GHz

Stop Frequency: 12.4 GHz

Number of Frequency Points: 801

Target Angle: 0



Figure

2-3.

Typical

Measurement

RCS

Setup

Typical Test Setup

Figure 2-3 shows a typical RCS setup. Notice that the reference signal is coupled from the RF

source rather than using a reference antenna as in an antenna measurement. This is a normal

conguration

monostatic

a

for

used

quasi-monostatic

a

for

range

and

bistatic

antenna

range

directional coupler

dual

A

.

is

Calibrate

Calibrate using the instructions provided in \RCS Calibration

" in Chapter 3.

Measurement Examples

Manual

2-13

Manual RCS Measurements

Choose Measurement Settings

1.

Select Frequency Domain measurements: Press

2.

Set the frequency sweep to Step mode: Press STIMULUS

4

DOMAIN

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

5

FREQUENCY

4

5

MENU

NNNNNNNNNNNNNN

STEP

.

NNNNNNNNNNNNNN

The

RAMP

sweep mode may be used with some frequency converters such as the HP

8511A/B if the proper rear panel connects are made. Refer to the Ramp Sweep mode

description in Chapter 4 for more information.

NNNNNNNNNNNNNN

3.

Press

MORE

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

CONTINUAL

.

4. Make sure the triggering is set to internal by pressing:

STIMULUS

4

MENU

NNNNNNNNNNNNNN

5

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

MORE

TRIGGER MODE

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TRIG SRC INTERNAL

With the trigger set to internal the receiver will not wait for an external trigger signal

before taking any data points. Instead, it will measure each point at the fastest possible

speed.

Also make sure that the

NNNNNNNNNNNNNNNNNNNNNNN

PARAM

Select

5.

3

the

NNNNNNNNNNNNNNNNNNNNNNN

and

,

PARAM

measurement

NNNNNNNNNNNNNNNNNNNNNNNNNN

STIMULUS

not.

are

4

frequency

key is underlined, but the

range and

the number

NNNNNNNNNNNNNNNNNNNNNNN

PARAM 1

of points

NNNNNNNNNNNNNNNNNNNNNNN

,

PARAM 2

by pressing

the

keys:

,

following

4

ART

ST

4

STOP

STIMULUS

Note

5

12.4

5

G/n

4

5

G/n

4

5

MENU

When

frequency

measurement

high

N

NUMBER

using

N

NN

N

OF

HP

an

change

N

POINTS

8360

used

is

accuracy

NN

N

801

family

to

N

RF

accurately

required,

is

source,

phase

use

the

rst

lock

second

sweep

RF

the

any

after

frequencies

sweep

for

your

4

8.2

5

measurement.

Select the

6.

4

PARAM 1

parameter you

5

wish to

measure,

7. Determine an appropriate RF power level for your range. Most RCS setups use the

maximum available power.To change RF power: Press STIMULUS

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

POWER SOURCE: 1

target

the

Set

8.

Choose Display F

. Then enter the desired value, or use the knob.

in

place

at the

,

desired

ormat

Choose a data presentation format, scale

press:

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

4

5

POWER MENU

positioner

angle

MENU

.

, and reference value/position as explained in \Angle

Scan Measurements".

If

.

,

Manual Measurement

2-14

Examples

Manual RCS Measurements

Measure the Target

The receiver will already be measuring RCS data. By default, the receiver will measure the

frequency band repeatedly. After the target has been measured, you can stop taking data by

pressing:

NNNNNNNNNNNNNN

STIMULUS

4

MENU

5

MORE

NNNNNNNNNNNNNN

HOLD

or

You can make a single sweep measurement by pressing:

NNNNNNNNNNNNNN

STIMULUS

4

MENU

5

MORE

NNNNNNNNNNNNNNNNNNNN

SINGLE

You can now remove the target or make other changes while performing other functions

and data processing on the RCS measurement. An example of a Frequency Domain RCS

measurement is shown in Figure 2-4.

After the measurement is nished you can save the data to disc, refer to Chapter 6 for

instructions.

Figure 2-4.

If you want to measure

Press STIMULUS

receiver

will underline the

4

MENU

receiver is in Hold mode

Frequency

Typical

RCS

one sweep at a time:

5

NNNNNNNNNNNN

NN

MORE

NN

NNNNNNNNNNNNNN

HOLD

NNNNNNNNNNNNNNNNNN

SINGLE

. The receiver will take one sweep

softkey when the measurement is nished. This means the

, and is not making measurements

Domain

. The letter

left-hand side of the display when the receiver is in Hold mode.

Measurements

our

Y

Choose

The

the

dierent

Single P

Ramp Sweep

oint

Best

sweep

mode

Sweep

modes

Mode

under

for

STIMULUS

4

MENU

5

are:

Measurement

, then stop

H

will appear on the

Measurement Examples

Manual

. The

2-15

Manual RCS Measurements

Step Sweep mode

Frequency List mode

Refer to \Frequency Domain Measurement Tutorial" in Chapter 4 for information on these

modes.

Choose Single or Continual Measurements

NNNNNNNNNNNNNN

You can also choose between single or continual measurements, using STIMULUS

NNNNNNNNNNNNNNNNNNNN

SINGLE

NNNNNNNNNNNNNNNNNNNN

SINGLE

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

or

CONTINUAL

.

makes a single measurement. When the measurement is done the instrument

4

MENU

5

MORE

switches to Hold mode.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

CONTINUAL

repeats the measurement continuously.

Using Markers

Markers can be used to give detail of specic points on the trace.For example, to show the

largest RCS response, press:

4

MARKER

NNNNNNNNNNNNNNNNNNNNNNNNNN

5

MARKER 1

NNNNNNNNNNNNNN

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

MORE

MARKER to

MAXIMUM

:

Time

The

the

Domain

down

Converting

convert

o

T

4

DOMAIN

detailed

or

F

Manual

such as:

to

NN

N

5

TIME

. This manual discusses important factors that aect a Time Domain measurement,

Alias-Free Range,Range Resolution,Response Resolution

Frequency

the

N

information

Measurements

Domain

response

RCS

N

NN

N

PASS

Domain

Domain,

N

to

N

BAND

Time

N

on

measurement

be

can

press:

Domain,

Time

seen.

Choose the Display Format

Y

4

ou

LIN

may

MAG

wish

,

5

4

LOG

to

MAG

set

display format.

the

FORMA

or

5

T

4

MENU

N

5

The

N

REAL

Since you are now in the Time Domain, the

rather than frequency

. This means that the following keys now

adjust or measure in time:

4

5

START

4

5

STOP

4

CENTER

4

SPAN

4

MARKER

5

into

Programming

and

,and

Impulse Waveforms

Domain

Time

for

see

N

NN

N

most

N

can

the

be

now

8530

HP

common

converted

Operating

formats

Domain.

Time

.

X-axis of the data display is now showing time

aect the Time Domain, and

are:

Thus

.

,

example

an

As

converted

been

Manual Measurement

2-16

of

into

an

measurement,

RCS

Time

a

Examples

Domain

Figure

the

measurement

Frequency Domain

2-4

and

shown

in

Figure

measurement

.

2-5

has

Manual RCS Measurements

Measure the Target

The display is now showing the measured Time Domain response. Markers can be used to nd

the magnitude and the location of each reection.

Using

Markers

earlier

display

the

can

in

is

this

in

Markers

be

now

chapter

Angle

the

Figure

used to

learn

to

Frequency

,

Typical

2-5.

measure each

use

to

how

Time

or

,

RCS

the

of

this

domain.

Domain

Time

responses

markers

Measurement

See

.

The markers

.

\Using

work the

Markers"

same

Chapter

in

if

5

the

Manual

Measurement Examples

2-17

Manual RCS Measurements

A Quick Display Adjustment

If the Time Domain display has not already been adjusted in an earlier measurement, the

following is a quick method to get a good data display.

To adjust the magnitude response so that you can see the data, press:

4

5

AUTO

To make sure that you are getting all of the data on the time axis, set the STOP time well

beyond the last time response. A good example is:

4

5

300

4

5

STOP

Press

4

AUTO

for a 150 foot range.

G/n

5

again to make sure all of the response data can be seen on the display.

Look for the rst point at which the response starts repeating itself (this is due to aliasing).

Figure 2-6 shows an example of this.Adjust the stop time to this point by:

4

MARKER

5

Use the knob to move the marker to just before the start of the repeating response, or to the

last point that there is an RCS response.

Press:

The

4

SCALE

4

STOP54=MARKER

4

,

REF V

will

ALUE

Display

5

now

,

5

be

and

5

.

showing

others

the full

desired.

as

RCS response

.Y

ou can

now

adjust

the

4

START

5

,

4

STOP

,

5

Manual Measurement

2-18

Figure 2-6. Time Domain Measurement Showing Aliasing

Examples

Manual RCS Measurements

Improving RCS Measurement Accuracy

Many of the RCS responses are due to error signals and not due to the target response. Some

of the error signals are; coupling, monostatic antenna return loss, chamber reections and feed

clutter. An RCS calibration can remove or reduce some of these errors. Time domain

Gating

can also be used to reduce some of the errors, such as bistatic coupling, antenna return loss,

and chamber reections.

Gating works like a Time Domain \band pass" lter. The gate is placed around the response

that you wish to keep, the gate is turned \ON", and the responses outside of the gate are

ltered out. Just like a frequency band pass lter, gating has time response sidelobes, lter

skirt, and in-band ripple.For detailed information on gating, see the Time Domain section in

the

HP 8530 Operating and Programming Manual

.

Using Gating

To show how to use the gate, we will use the earlier RCS Time Domain example.To get to the

gating softkeys, press:

4

DOMAIN

the

Use

around

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

5

TIME BANDPASS

N

NN

N

GATE:

START

the response

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

SPECIFY GATE

N

NN

N

that

and

N

you

N

STOP

N

NN

N

wish

keys

to

or

keep

N

the

CENTER

(normally

N

NN

N

and

target

the

N

SPAN

NN

N

NN

keys

response).

to

center

the

gate

ags

A Measurement Showing the Gate Placed Around the Response

Now turn the gate \ON" by pressing:

N

NN

N

ON

GATE

Figure 2-7.

Manual

Measurement Examples

2-19

Manual RCS Measurements

ON

removed.

response

made

channels

, format,

errors too

by using

signal we

allow independent

domain (except

The

.

the

are going

to

section

.

use

angle),

both

o

show

that

also

will

use

how

Frequency

the

Notice

Gating

shows

Viewing

T

measurement

adjustment

and

parameter

,

responses outside

the

in

work

receiver

both

dierences

channels

the

of

more

of

various

.

Figure

Frequency

the

channels

Time

and

between

receiver

the

display

2-8.

gate

the

of

Domain

show

to

Domain

signal

gated

a

The

.

parameters

Gate

The

have

to

the

Gating

and

measurement

two

such

,

Turned

been

reduce

dierences

un-gated

an

scale

as;

To set up for this example, return to the basic RCS measurement by turning gating o, markers

o, and selecting Frequency Domain.

Press:

4

DOMAIN

4

PRIOR

4

MARKER

5

SPECIFY

MENU

NNNNNNNNNNNN

5

all OFF

N

NN

N

5

FREQUENCY

NNNNNNNNNNN

NN

To display both measurement channels

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

NNNNNNNNNNNNNNNNNNNNNNNNN

4

DISPLAY

NNNNNNN

5

DISPLAY MODE

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

You can also press

.

side

by

side

NNNNNNNNNNNNNNNNNNNNNNNNNN

GATE

N

NNNNNN

N

NN

N

NNNNNNN

GATE

NNNNNNNNNNNNNNNNNNNNNNNNN

OFF

DUAL CHANNEL

GRATICULE OVERLAY

, press:

NNNNNN

NNNNNNNNNNNNNNNNN

or

SPLIT

, to view the two traces superimposed, or

Currently

changes

any

4

CHANNEL

2-20

2

Manual Measurement

channel

you

.

5

is

1

make

the active

aect

will

Examples

channel

channel.

that

(notice

T

the

make

o

lit

LED

channel

above

4

the

the active

2

CHANNEL

channel

5

1

key),

press:

and

Manual RCS Measurements

Now make the channel 2 display just like the channel 1 display.To do this use the

4

SCALE

5,4

REF VALUE

5,4

REF POSN

5

,and

4

FORMAT

5

keys. If you press the

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

N

GRATICULE OVERLAY

4

PARAM

5

,

key

you will notice that both channels display the same information.

Now change both channels to the Time Domain. Notice that you can change the domain in

both channels separately. This allows you to display the frequency response on one channel

and the time response on the other.

Press:

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

4

CHANNEL 154DOMAIN

4

CHANNEL 254DOMAIN

5

TIME BANDPASS

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

N

5

TIME BANDPASS

Also notice that channel 1's Time Domain display is set for the same settings that were made

earlier. Now make channel 2's Time Domain response display the same as channel 1.

Now turn on the gating around the target response in channel 2. Again notice that the gate is

still in the same place we left it earlier in this example.

Press:

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

N

SPECIFY GATE

now

can

ou

Y

shows

an

NNNNNNNNNNNNNNNNNNNNNNN

compare

example

GATE ON

the

this

of

dierence

.

between

the

gated

and ungated

responses.

Figure 2-9

Figure 2-9. Dual

Display with Time Domain

Now change both channels back to the Frequency Domain, leaving the gate ON in channel 2,

press:

N

NN

N

4

CHANNEL

4

CHANNEL

4

5

2

DOMAIN

N

NN

N

5

FREQUENCY

1

N

5

FREQUENCY

N

Measurement Examples

Manual

2-21

Manual RCS Measurements

Notice the changes in channel 2 as compared with channel 1. Channel 2 has many of the

RCS responses reduced by using the gating capability of the receiver. An example of this is in

Figure 2-10.

Dual

2-10.

Domain to

Time

gate

turn

to

N

NN

GATE ON

at

N

of

N

on

NN

the

where

the

proper

don't

ou

Y

Frequency

Domain,

whenever

Then,

4

DOMAIN

5

into

go

to

have

a

N

prior

you

N

Set

wish

N

NN

N

Domain.

by

or

N

NN

N

SPECIFY GATE

Figure

the

knowledge

N

NN

without ever going into the Time Domain.

Display

turn ON

location, either

the start

press:

,

gate

with Time

gate

the

and stop

Domain

are

you

if

by adjusting

point

only

would

measuring

gate

the

for

be

in

gate

the

Time

.

Manual Measurement

2-22

Examples

3

Antenna and RCS Calibration

This chapter explains antenna and RCS calibration features of the HP 8530A. Network analyzer

calibration features are documented in the

Chapter Contents

What is Calibration?

Calibration Requirements

Calibration Menu Map

Antenna

Standard

erforming

P

RCS

Calibration

Gain Antenna

an

Calibration

Antenna

Denitions (les)

Calibration

HP 8530A Operating and Programming Manual

.

Antenna

and RCS

Calibration

3-1

Calibration Fundamentals

Information Pertaining to All Calibration Types

What is Calibration?

Calibration, regardless of the exact type, reduces repeatable systematic errors caused by the

system, the chamber, or the antenna range.To achieve this, the receiver measures one or more

standards of known characteristics. During calibration, the receiver:

1. Measures the standard.

2. Compares the results to the known characteristics of that standard.

3. Calculates the exact amount of inaccuracy, and how much the measurement data must be

adjusted to compensate for it. The adjustment values are called \error coecients."

4. Stores the error coecients in memory.

When actual measurements are made, the calibration feature subtracts the error coecient

values, making the measurement much more accurate.

The HP 8530A can perform three types of calibration:

expressed

Antenna

Calibration

Antenna

dBi

in

gain

calibration

(dB

antenna

frequencies

relative

with

used

is

allows

an isotropic

to

known

transfer

a

as

measured data

radiator). A

dened gain

or

standard

to be

standard

values at

to calibrate

specic

the

system.

Calibration

RCS

Network Analyzer

Response

a

using

Response

calibration

the

empty

clutter

antenna

.

expressed in

Calibration Network

systematic errors

A network

your calibration standards to the measurement of your

device. Network analyzer calibration standards are supplied

in a \calibration kit" which must be purchased separately.

Calibration kits are made for specic frequency ranges and

connector types.

Background

and

calibration

portion

target

of

target.

the

The

chamber

performing

After

dBsm (decibels

analyzer calibration

during network

analyzer calibration

calibration

known

of

calibration

Background

characterize

to

RCS

an

square

per

greatly

transfers the

errors

reduces

radar

measures

portion

calibration,

range

section.

cross

the

measures

compensate

and

measurements

reections

meter).

reduces

repeatable

analysis measurements

accuracy

The

of

the

for

are

.

of

3-2

Antenna and

RCS

Calibration

Calibration Fundamentals

Calibration Requirements

Calibration issues become much simpler if you calibrate using the same equipment and

instrument settings that you plan to use during the measurement.

Use the Same Equipment Setup in the Measurement

You

must

calibrate using the same adapters and cables that will be used for the measurement.

If the adapters or cables are changed between calibration and measurement, unpredictable

errors will result due to the fact that the error coecients determined during calibration are

incorrect for the altered setup. Even disconnecting and reconnecting the same adapter can

cause inaccuracy. If you change the setup, you must perform the measurement calibration

procedure again to calculate appropriate error terms for the new setup.

Settings You Can Change after Performing a Calibration

1. You can perform a network analyzer calibration in the frequency Domain, then change to

time domain, and the calibration will remain valid.

2. You can calibrate using a specic number of points, then make a measurement using a

smaller

Y

3.

or

some

ou

can

Time

HP

number

perform

Domain,

8530

of

an antenna

the

and

receivers

calibration in

calibration

the

turn

still

will

calibration

the frequency

valid.

be

must

ou

Y

.

OFF

domain, then

change

you

(If

manually

change

the

to

turn

the

to

Angle Domain,

calibration ON

the

Angle

.

points

again.)

select

4.

can

ou

Y

Single

perform

frequency

swept

a

frequency

measurement.

calibration

(Some

HP

8530

Ramp

(in

receivers

Step

or

require

sweep

you

mode),

turn

to

then

calibration

the

ON again.)

can

ou

5. Y

Setting

settings can

Other

and

change

start

Changes that

be changed,

in

while

angle

stop

Require Special

but require

special

Angle

Domain.

Consideration

consideration.

Changing Parameter

The HP 8530A automatically turns calibration OFF if you change parameter. However,it

allows you to turn the calibration ON again for the new parameter. If you are not careful,

this can result in invalid data. There are situations (explained below) where you can change

important

parameter

know

must

instrument will

The

and

when

get

valid

the

measurement

results

warn

not

are valid,

you.

results.

and

The

avoid

situations

To understand the considerations involved, remember that

hardware

way).

As long

setup (a specic collection of cables

, adapters

as the parameter you select will measure that equipment as it was originally set

, and so forth, connected in one specic

remember

to

thing

where

invalid

data

a calibration applies to a specic

is

would

result.

you

that

up, the calibration will be valid.

For example, assume you originally connected the equipment to inputs b1 and a1, and

performed the calibration using b1/a1 ratio.You can select any parameter key that is currently

dened

as

b1/a1

the calibration

and

will

be

valid.

(Y

ou

can

redene

any

parameter

key

be

to

b1/a1.)

a

Antenna

and RCS

Calibration

3-3

Calibration Fundamentals

Changing Stimulus Values

Changing any of the following settings will cause the message

INVALID

to be displayed. Calibration remains ON.

CAUTION: CORRECTION MAY BE

Source Power

Power Slope

Dwell Time

Sweep Time

Sweep Modes

Trim Sweep Value

Settings that should not be changed

Selecting a Dierent Frequency Range

If you have performed any type of calibration across a frequency range, and then change

frequencies, calibration is automatically turned O, and

oints

P

Selecting

you

If

greater

a

calibrate

number

automatically

Greater

using

points

of

turned

Number

certain

a

If

.

and

O,

of

number

attempt

you

CORRECTION

of

points

select

to

RESET

,

you

CORRECTION RESET

cannot

greater

a

displayed.

is

perform

number

is displayed.

measurement

a

points

of

calibration

,

using

a

is

veraging

Using

or

F

device

Hewlett-P

of

accomplished

factor

A

calibrations

all

measurement.

ackard

calibration

the

the active

as

use

,

recommends

RCS

(in

turning

by

function during

the

general,

In

calibration

veraging

A

same

that

greater

or

averaging

an

use

increase

you

the

is

this

before

ON

the calibration.

averaging

factor

the

background

beginning

factor

of

averaging

calibration).

the

will

than

for

16

or

8

factor

for

calibration,

be

most

for

used

measurements

isolation

the

can

This

leaving

then

the

portion

easily

be

averaging

If you are using averaging

If averaging is ON during calibration, then the correct number of measurements needed

to provide fully averaged data are automatically taken. For Ramp sweeps this means that

n+1 sweeps, where n is the current averaging factor, are taken. For Step,SinglePoint, or

Frequency

List,

each

data

point

averaged

is

times (where

n

selected

the

is

n

number

of

averages).

.

3-4

Antenna and

RCS

Calibration

Calibration Fundamentals

Figure 3-1. Cal and Cal Type Menus

Antenna

and RCS

Calibration

3-5

Calibration Fundamentals

Specic Calibration Procedures

The following pages contain information about specic types of calibration, including

step-by-step procedures on performing calibrations.

The receiver provides the following calibration types:

Antenna Calibration

RCS Calibration

Network Analyzer Calibration (only described in the operating and programming manual)

Response Calibration

Response and Isolation Calibration

1-Port Calibration

3-6

Antenna and

RCS

Calibration

Antenna Calibration

Antenna calibration allows measured data to be expressed in dBi (dB relative to an isotropic

radiator). A standard gain antenna with known or dened gain values at specic frequencies is

used as a transfer standard to calibrate the system.

Calibrating with a standard gain antenna corrects for the transmission response errors.

An optional part of antenna calibration is an \isolation calibration." This calibration reduces

crosstalk errors between input channels. The isolation cal requires a high quality RF load as a

calibration standard. The load you need is determined by the connector type and frequency

range of your system.

Important Terms

Cal \Cal" is an abbreviation for \Calibration."

Cal Denition A cal denition is an ASCII le you create using a text editor. It contains

theoretical or measured frequency and gain values for the standard gain

antenna. You can create the le using any computer-based text editor

which can save text in plain ASCII format. The le can then be loaded into

Antenna

Denition

receiver

the

\antenna

data

gain

The

denition."

a

from

denitions

a

for

or

DOS

."

specic

disc

LIF

standard

.

A

gain

denition

cal

antenna

contains up

called

is

\antenna

an

to seven

more

the

sets

gain

antenna

These

."

nal

can

be

Set

Cal

Angle

Domain

nished

A

antenna

denitions

dierences

calibration

measured

is

Any

.

are

measurement,

measurement

internal

stored

in

Frequency

and

dierences

error

the

result

is

data

registers

le

data

performance

its

and

are

coecients

calibrated

in

expressed

or

Domain

During

.

stored

the

in

which,

.

results

of

units

in

.

disc

to

Calibrations

calibration,

compared

is

internal

an

when

antenna calibration,

In

antenna gain

the

to

\cal

subtracted

(dBi). Cal

standard

or

one

register

set

from

If you perform a calibration while in angle domain, the calibration will be at one frequency.

(Angle Domain makes measurements at only one frequency.)

If you perform a calibration while in Frequency Domain, you can calibrate over a range of

frequencies.

Using a

Frequency

HP recommends

that

Domain

calibrate

you

Calibration

Frequency

using

in

Angle

Domain.

Domain,

which

calibrates

over

range

a

of

frequencies.You can then switch to Angle Domain, and pick any of the frequencies from the

Frequency Domain calibration. This gives you instant access to many calibrated frequencies

(one at a time) when in Angle Domain.

Only one limitation applies; the frequency you want to measure (in angle domain) must exist in

the original calibration. The receiver does not interpolate between calibrated frequencies

.

Here are the basic steps involved in antenna calibration:

Antenna

and RCS

Calibration

3-7

Antenna Calibration

3-8

Antenna and

RCS

Calibration

Antenna Calibration

Standard Gain Antenna Denitions

To perform a calibration, the receiver must know the published gain values of the standard

gain antenna. HP has supplied a le containing data for seven Narda standard gain horns.

If You Are Using a Narda Standard Gain Horn that is Already Dened:

Data for Narda models 638, 639, 640, 642, 643, 644, and 645 are supplied in a single cal

denition le.Thisle,

with the HP 8530A. If you are using one of these horns, load

AC_NAR1

, is supplied on the

Antenna/RCS Cal Disc

AC_NAR1

as explained below:

which was shipped

1. Insert the

2.

Press

showing

Antenna/RCS Cal Disc

4

DISC

AC_NAR1

NNNNNNNNNNNNNN

5

NNNNNNNNNNNNNNNNNNNNNNNNNN

LOAD

CAL KITS

. Since it is the only cal denition on that disc, it will already be

into the HP 8530A's disc drive.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

ANTENNA CAL DEF

, the receiver will display a le directory

highlighted.

Press

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

LOAD FILE

.

3.

When you perform the antenna calibration you will see the Narda horns listed in a softkey

menu. Information on the Narda horns is provided at the end of the calibration section. Please

note that your Narda standard gain horn calibration data may be dierent than the data on le

ou

save

.

Are

your

Not

",

text

cal

end

plain

you

If

One of

denition

of

ASCII

calibrate

own

at

in

Using

the

more standard

what happens

frequencies?" The

the calibration

the Pre-Dened

as

le

chapter

this

format.

over

antennas

gain

when

answer

data for

explained

will

ou

Y

.

wide

a

the

of

two

is:

standard

the

Narda Horns:

\Creating

in

personal

a

need

frequency

Some

.

range

users

standard

Where

the

gain

Standard

a

computer

may

you

,

asked

have

antennas

gain

frequencies

antenna

that

Gain

and a

need

\When

us:

have

overlap

was

Antenna

text editor

two

use

to

calibrating,

overlapping

receiver

the

,

measured

that

or

uses

last.

AC_NAR1

Y

If

Create

Denition

can

Note

Performing an Antenna Calibration

Frequency Domain Calibration

Finding Boresight

,

1.

Setup

Mount

the

standard

gain

antenna

on

the

proper

Initial

system.

2.

Press:

3.

Press:

4.

Press: STIMULUS

5. Press

4

RECALL

4

DOMAIN

4

CENTER

frequency

4

Press

6.

7.

Select

MARKER

the

NNNNNNNNNNNNNN

5

NNNNNNNNNNNNNNNNNNNNNNNNN

MORE

FACTORY PRESET

NNNNNNNNNNNNNNNNNNNN

NNNNNNNNN

FREQUENCY

NNNNNNNNNNNNNNNNNNN

4

5

MENU

5

and enter a frequency in the approximate center of the calibration

.

range

.

5

desired axis

on

NNNNNNNNNNNNNNNNNNN

.

NNNNNNNNNNNNNNNNNNN

SINGLE POINT

positioner

the

.

controller

antenna

.

mount

and connect

Antenna

and RCS

your

to

it

Calibration

3-9

Antenna Calibration

8. Move the positioner so the antenna is somewhere near its boresight position (a rough

approximation is ne).

9. Move the positioner until the at line reaches maximum amplitude (or minimum amplitude

if your antenna has a null at boresight). It is helpful to watch the marker value readout (in

the upper-left portion of the display). This digital readout of the amplitude makes it easy

to observe small (0.1 dB) changes.

10. Boresighting is usually interactive between axes, so repeat steps 5, 6, and 7 for each axis

until true boresight is found.

Choosing Calibration Stimulus Settings

1. Perform step a or b below, depending on if you want to calibrate at one or more frequency

points.

a. If you only want to calibrate at a single frequency press STIMULUS

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

SINGLE POINT

Calibration Steps

. Press

,below.

4

CENTER

5

followed by the desired frequency, proceed to

4

MENU

5

b. To calibrate over a range of frequencies, you must choose a sweep mode. Any mode

Note

will work

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

STEP

the

sweep

the

inconvenient

size

Sometimes

cover the

to

during

but the Frequency List mode is strongly recommended

NN

increment frequency

N

NN

of

the

in

STEP

,

function

not

use

to

case

the

function

SIZE

Frequency

modes

increment

convenient

is

that

Ramp

congured.

source

receiver

wide frequency

whole frequency

the procedure

allows

mode

List

allow

only

frequency

increment

Sweep

addition,

In

.

and

below.

is

you

.

values

.

mode

Ramp

the

you

better

to

This

is not

Sweep

RF

ranges

to

choose

limits

(like

Ramp

source

range

enter

when

a

exibility

17.67

always

mode

Sweep

.

require

this

If

.

a

known

performing

NN

N

NUMBER

MHz).

usable

will

requires

you

is

calibration.

a

N

NN

N

POINTS

calibration

SIZE

depending

is

BNC

two

or

two

enter

,

. The Frequency List

. This

N

and

,

allows

on

systems

the

and

how

often

you

your

that

receiver

to

and

Ramp

N

connections

standard

more

the

entire

frequency

results

choose

system

use

between

gain

To use Frequency List mode, as recommended, perform the following sub steps:

NNNNNNNNNNNNNN

i.

Press STIMULUS

Press

8.2

Press

NNNNNNNNNNNNNN

EDIT

GHZ).

N

STOP

N

NNNNNN

STEP SIZE

ii.

iii.

iv.

N

NN

N

NNNNNNNNNNNNNNNNNNNNNN

4

5

MENU

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

SEGMENT: START

N

the

enter

and

and enter the desired frequency increment value

a moment that your standard gain antenna has documented

MHz. Y

ou can choose smaller increments (for example

interpolate between known

Press

NNNNNNNNNNNNNN

DONE

. The receiver will display the number of points it will use in the

v.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

MORE

EDIT LIST

.

and enter the desired start frequency (for example,

GHz).

12.4

desired

stop

frequency

(for

example

,

. Assume for

gain values every 50

MHz), and the receiver will

,25

gain points. (Straight-line interpolation is performed.)

measurement, based on the selected step size.

N

NN

N

Press

N

again.

DONE

N

NN

N

FREQUENCY

N

NN

N

LIST

N

Frequency

select

to

List

mode.

vi.

vii.

Antenna

why

is

step

chooses

in

a

an LO

antennas

step

is

the

range

3-10

Antenna and

RCS

Calibration

Antenna Calibration Steps

Antenna Calibration

2. Press the

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

ANT. CAL uWave A.1

4

5

key (located in the MENUS block), then press:

CAL

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

FAR FIELD:RESPONSE

A menu will appear with seven standard gain antenna denitions to choose from.

3. Select the denition for your standard gain antenna. If you must create a denition for your

standard gain antenna, refer to \Creating a Standard Gain Antenna Denition", at the end

of this chapter.

The receiver will now measure the standard gain antenna, and create a list of osets called

a \Cal Set."

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

If you only want to measure one standard gain antenna, press

DONE RESPONSE

and proceed

to \Finishing the Gain Calibration," below.

Note

If you see the error message:

CAUTION: ADDITIONAL STANDARDS NEEDED

,

the standard gain antenna does not cover the entire frequency range of the

calibration. You should do one of the following things:

additional

a. Measure

additional

an

standard

gain

antenna

to

cover

the

frequencies.

your

If

.

this

range

Make

entire

Refer

chapter

the

sure

frequency

for

le

the

to

.

of

range

that

the

Use

b.

antenna

standard

range

antenna

section

Select

c.

standard

a

is

that

of

may

on

calibration

a

specied

antenna

gain

antenna.

not

creating

antenna

gain

gain antenna

cover the

to

denition

The

entered

have

standard

frequency

and

that covers

selected frequency

really has

person

who created

values

antenna

gain

that

span

calibration

the

do

the

for its

denitions

within

is

entire

frequency

range:

entries for

\denition"

the

entire

range

the

again.

over

the

in

,

frequency

4.

than one

calibrating

are

you

If

for

frequency

wide

a

range

requiring

,

more

standard gain

antenna:

antenna.

a. Mount

the

gain

b. If necessary, boresight the antenna. You must stay in the current Domain and Sweep

Mode.For example, if you are currently in Frequency List mode, the receiver must

remain in this mode during boresighting or the calibration will be ruined. With a marker

still ON, turn the antenna until boresight (for that axis) is found. Turn the antenna in

small steps because of the delay between completed sweeps. Do this for each axis until

boresight is

c. Select

Repeat these

d.

e.

Press

If the error message:

found.

appropriate

the

sub-steps

NNNNNNNNNNNNNNNNNN

NNNNNNNNNNNNNNNNNNNNNNN

DONE RESPONSE

antenna

each

gain

standard

for

when you are done

gain

.

denition

antenna

from

you

CAUTION: ADDITIONAL STANDARDS

the

need

NEEDED

softkey

to

menu.

measure

.

appears, then the

denitions for your standard gain antennas do not cover the entire frequency range you

selected. There are either gaps between adjacent denitions

have

, or they do not provide

full coverage near the beginning or end of the frequency range.

Finishing the Gain Calibration

Y

5.

want

between

ou are

now

perform an

to

inputs

done

(either

gain

the

with

\isolation

calibration."

reference-to-test or

portion

calibration.

the

of

isolation

An

test-to-test),

you

Now

calibration

requires

and

should

reduces

a

decide

crosstalk

high-quality

if

50

you

load.

Antenna

and RCS

Calibration

3-11

Antenna Calibration

a.

If you

do not

want to perform an Isolation Calibration, press

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

OMIT ISOLATION

and

proceed to \Saving the Cal Set to a Cal Set Register."

b. If you want to perform an isolation calibration, refer to \Isolation Calibration," below.

Isolation Calibration

6. Replace the standard gain antenna with a 50  load. Make sure the load's connector is

torqued as shown in Table 3-1 to prevent RF leakage.

Table 3-1. Proper Connector Torque

Press

7.

Saving

8.

Press

register

The

NN

N

ISOLATION

the Cal

NN

N

SAVE

softkeys

receiver

N

NN

Set

N

NN

FAR

will

N

to

N

Connector Torque

cm-kg

Torque

N-cm

Torque

in-lbs

Part Number

Type-N 52 508 45 8710-1935

3.5 mm 9.2 90 8 8720-1765

SMA 5.7 56 5 8710-1582

2.4 mm 9.2 90 8 8720-1765

N

receiver

The

.

Cal

a

N

NN

N

FIELD

and

.

the

turn calibration

now

R

Set

menu

A

cal set

will

egister

of

will

perform

cal

eight

saved

be

ON,

so

isolation

the

registers

set

that

to

measurement

any

calibration.

will

register

Wrench

appear

.

you

Press

.

make

will

any

be

eight

the

of

calibrated.

3-12

Antenna and

RCS

Calibration

Antenna Calibration

Angle Domain Calibration

Initial Setup, Finding Boresight

1. Mount the standard gain antenna on the proper antenna mount and connect it to your

system.

2.

Press

4

RECALL

3.

Press

4

DOMAIN

4.

Press STIMULUS

5.

6.

7.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Press

FREQUENCY OF MEAS

NNNNNNNNNNNNNN

Press

MORE

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Press

TRIGGER MODE

NNNNNNNNNNNNNN

5

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

CONTINUAL

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

MORE

FACTORY PRESET

NNNNNNNNNNNNNNNNN

ANGLE

.

4

5

MENU

.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TRIG SRC FREE RUN

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

SINGLE ANGLE

.

, then enter the desired calibration frequency.

.

8. Select the desired parameter,

9.

Turn on

Now

10.

Marker

particular

Repeat

11.

back

Antenna

Press

1.

N

ANT.

menu will

A

Select the

2.

standard

of this chapter.

The receiver will now measure the standard gain antenna, and create a list of osets called

a \Cal Set."

Press

Finishing the

Marker

positioner

the

use

When

1.

.

axis

each

for

forth

and

Calibration

4

the

N

NN

N

CAL

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

DONE RESPONSE

key

5

CAL

N

NN

N

uWave

appear

denition for

gain antenna,

Gain

pressing

by

1

marker

the

if

,

axis

between

Steps

(located

N

A.1

with

and proceed to \Finishing the Gain Calibration," below.

Calibration

N

FAR

your

refer to

4

PARAM 1

4

MARKER

controls

necessary

axes

N

seven

to

reaches

Boresighting

.

until

MENUS

in the

N

NN

N

FIELD:RESPONSE

standard

\Creating

5,4

5

move

peak

the

N

NN

N

gain

true

N

PARAM 2

NNNNNNNNNNNNNNNNNNNNNNNNNN

MARKER 1

the antenna.

block),

N

gain

a

5,4

you

value

is

boresight

N

antenna

antenna.

Standard

PARAM 3

.

Watch

have

iterative

is

press:

then

denitions

you

If

Gain

5

,or

found

so

found.

must

Antenna

4

PARAM 4

the data

the

may

you

choose

to

create

Denition

5

.

readout for

boresight

have

from.

denition

a

",

for

measure

to

at

that

the

for

your

end

should

NNNNNNNNNNNNNNNNNNNNNNNNN

NNNNN

OMIT ISOLATION

load's

the

Antenna

Make

Now you

sure

calibration.

the

with

of

Set Register."

load.



50

a

leakage

RF

.

portion

gain

the

with

done

now

are

ou

3. Y

want to perform an \isolation calibration." An isolation calibration reduces crosstalk

between inputs (either reference-to-test or test-to-test), and requires a high-quality 50 load.

a.

If you

proceed to \Saving the Cal Set to a Cal

b. If you want to perform an isolation calibration, refer to \Isolation Calibration," below.

Isolation

Replace

4.

torqued

do not

Calibration

the

as

want to perform an Isolation Calibration, press

antenna

in

gain

able

T

to prevent

3-2

standard

shown

decide

NNNNNNNNNNNNNN

connector

and RCS

if

and

is

Calibration

you

3-13

Antenna Calibration

Table 3-2. Proper Connector Torque

Connector Torque

cm-kg

Type-N 52 508 45 8710-1935

3.5 mm 9.2 90 8 8720-1765

SMA 5.7 56 5 8710-1582

2.4 mm 9.2 90 8 8720-1765

5. Press

Saving the Cal Set to a Cal Set Register

6.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

ISOLATION

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Press

SAVE FAR FIELD

register softkeys and the cal set will be saved to that register.

The receiver will now turn calibration ON, so any measurement you make will be calibrated.

. The receiver will perform the isolation calibration.

. A menu of eight cal set registers will appear. Press any of the eight

Torque

N-cm

Torque

in-lbs

Wrench

Part Number

3-14

Antenna and

RCS

Calibration

Antenna Calibration

Important Note On Antenna Measurements

Before you make actual measurements (with calibration ON), IT IS VITAL THATYOU READ

THE FOLLOWING:

The frequencies you measure must exactly match the frequencies in the cal set le.

For example, assume you have calibrated from 10 GHz to 11 GHz with a step size of 100 MHz.

The calibrated frequencies in the cal set are:

10.0 GHz 10.6 GHz

10.1 GHz 10.7 GHz

10.2 GHz 10.8 GHz

10.3 GHz 10.9 GHz

10.4 GHz 11.0 GHz

10.5 GHz

You can measure any of these frequencies during the actual measurement. You cannot,

The

GHz.

however

receiver

measure

,

does

any

interpolate

not

other

frequencies

between frequencies

or example

.F

in the

you

,

cal set.

cannot

measure

10.55

performing

know

to

again.

Angle

the

when

what

measure

using the

Angle

RESET

The

Domain.

and

frequencies

that

with

Frequency

Domain.

Simply

.

Frequency

You

calibration

the

can select

another

is

This

Thus

you

N

a

,

to

you

save

will

NN

N

Entering

set.

Things

Assume

and

receivers

N

NN

CORRECTION

calibration

frequencies

the

known,

know

you

Try

created

the

now

N

NN

ON

still

is

reason

convenient

cal

display

N

NN

CAL

valid,

the

in

why

precisely

calibration

a

to

set

the

N

SET

even

original

Frequency

size

step

which

in

Register

Set

Cal

message

NN

turn the

to

1

though

Frequency

List mode

makes

frequencies

Frequency

the

1.

CAUTION:

calibration ON

are

you

Domain

is so

easy

it

you

Now

CORRECTION

in

now

calibration,

useful

can

Domain,

go

the

valid.

Now change the start and stop angle, notice that the calibration remains valid.

calibrations

in the

are

calibration.

mode

List

4

CAL

8530A

Some HP

press

Domain

any

will remain

.

cal

,

5

of

Antenna

and RCS

Calibration

3-15

RCS Calibration

RCS Calibration Description

This section explains how to perform an RCS calibration. RCS Response and Background

calibration reduce range errors using a calibration target of known radar cross section. The

Response portion of the calibration reduces phase and amplitude discrepancies between

the test and reference channels (tracking errors). The Background portion measures the

empty antenna chamber to reduce undesired reections (clutter). After performing an RCS

calibration, log magnitude measurements are expressed in decibels per square meter (dBsm).

You should become familiar with concepts presented in the Time Domain chapter before

performing an RCS calibration.

Important Information about Gating During the Calibration

Keep the following in mind if using gating during RCS calibration:

After the RCS calibration is completed, the calibrated response of the Calibration Target

will move, and the gate will no longer be centered around it. To make sure that you do not

gating

,

the

turn

turns

gating

target

back

will

accidentally leave

OFF once

ON and

0.00

at

calibration is

center it

seconds

.

the gate

around

around the

done.

response

the

When

you

of

(now

old

perform

your

incorrect)

actual

RCS

measurement

position,

the

measurements

target.

Usually

receiver

be

Remember

are

ou

Y

using

If

gating

,

has

measuring

frequency

a

limitations

limited

a

where

list

not

Do

.

frequency

points

the

use

span

gating

or

are

if:

number

evenly spaced.

not

of points

.

3-16

Antenna and

RCS

Calibration

RCS Calibration Overview

RCS Calibration

Figure 3-2. Menus Associated with RCS Calibration

1. Determine the requirements of your measurement, including:

a. Stimulus Settings

Range

b.

Alias

c.

Gating

d.

These requirements will determine the stimulus

2. Select

3. Select stimulus settings

Resolution

Range

Free

Requirements

Frequency Domain

,

and gate settings you should use

, window

,

using one of the following methods:

Set start and stop frequency and number of points. This method is acceptable if you are

performing RCS calibrations for use in the Time Domain.

Use Frequency List mode with a start frequency, stop frequency, and a specic frequency

value

step

calibration.

Angle

the

This

.

This

Domain.

method

Why?

allows

preferable

is

Because

you

to

you

know

you

if

can

the

are

then

exact

going

make

frequencies

make

to

calibrated

represented

measurements

RCS

measurements

Antenna

and RCS

Calibration

in

at

.

the

in

any

3-17

RCS Calibration

frequency that exists in the calibration. (Remember, when making actual measurements,

the receiver cannot interpolate between calibrated frequencies.)

4. If desired, turn ON gating.

5. If desired, turn ON Averaging.

6. Specify RCS target type and its physical dimensions.

7. Perform the actual RCS calibration.

8. After the calibration, use

changes occur to the background. This updates the calibration so it is accurate given the

new background conditions.

RCS Calibration Procedure

As mentioned above, rst determine the needs of your measurement, then use the information

in Chapter 13, Time Domain Measurements, to calculate required start frequency, stop

frequency, and number of points, or the Frequency List mode settings required.

Select Stimulus Values

required

Frequency

Gating

is

Gating

If

a.

OFF

Press

Next,

is

the

Desired)

(if

explained

as

are

you

THIS

.

4

5

CAL

determine

display

use

to

List

the

in

explained

going

VERY

IS

N

CORRECTION

Enter

1.

the

Select

Gating

Use

2.

b.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

UPDATE BACKGROUND

.

Domain

below:

N

NN

N

OFF

location

values

a

ANT

N

frequency

mode

Time

perform

to

IMPORT

N

the

math:

gated

.

and

using

chapter

calibration,

width

if you change target mounts or if other

oints

any

of P

An

.

calibrations

way

Start,

.

the

of

Stop,

make

target

and Number

sure

response

using

by

or

,

are

this

to do

3-18

target

on

NNNNNNNNNNNNN

NNNNNNNNNNNNNNNNNNNNN

TIME BAND PASS

.

pressing

circumstances

5

the

5

4

DOMAIN

softkeys

shape by

gate

N

In

.

RCS

the RCS

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

DATA -> MEMORY

DEFAULTS

target

NNNNNNNNNNNNN

MATH (-)

5

most

Calibration

i. Remove

ii. Save the measurement to memory by pressing:

4

DISPLAY

iii. Select math subtraction mode by pressing:

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

SELECT

Place

.

iv

v. Select Data minus Memory mode by pressing:

4

DISPLAY

vi. Only the target response will appear on the screen.

c.

Press

d.

Choose the gate position and size using the gate

N

NN

N

SPAN

e.

Select

N

NN

N

MINIMUM

Antenna and

and

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

OPERATIONS

MATH

allow

mount,

the

NNNNNNNNNNNNNNNNNNNNNNN

and

NNNNNNNNNNNNNNNNNNNNN

SPECIFY GATE

N

GATE

,

SHAPE

the

N

NN

factory

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

MINUS

another full

NNNNNNNNNNNNNNNNN

N

, then

default (Normal)

receiver

the

allow

measure

to

(-)

.

NNNNNNNNNNNNNNNNN

START

either

one

measurement

NNNNNNNNNNNNNN

and

STOP

N

MAXIMUM

,

the

is

full

,or

N

WIDE

N

best

frequency

.

sweep

NNNNNNNNNNNNNNNNNNNN

CENTER

N

,

NORMAL

choice

N

and

N

sweep

N

,

.

or

f.

Turn Gating ON by pressing

g. Position the gate around the target response.

4

PRIOR MENU

NNNNNNNNNNNNNNNNNNNNNNN

5

GATE ON

RCS Calibration

.

If your target is a sphere, the placement of the gate is critical.

secondary reection caused by RF energy propagating around the back of the sphere,

which ultimately arrives back at the receive antenna. This produces the secondary

reection, known as a \creeping wave."

If the creeping clearly separate from the main target response, place the gate around

just the main response. In this case make sure you select the

when you dene the RCS target (the next step).

If the main target response and the creeping wave are not clearly distinct and

separate, position the gate around both of them. In this case make sure you select the

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TARGET: SPHERE

Do not attempt to gate out very large background reections, or subsequent measurements will

not be accurate.

Dene the RCS Target

select

to

is

The next

physical dimensions

3.

4.

step

4

Press

Select

N

CAL

the

N

NN

N

TARGET:

N

NN

N

TRIHEDRAL

N

NN

N

DIHEDRAL

N

5

MORE

type

N

SPHERE

N

.

NN

N

of

N

NN

N

model when you dene the RCS target (the next step).

during

use

N

NN

N

SPHERE

you

N

NN

SELECTION

one

N

NN

N

of

N

.

following:

the

N

NN

N

they

N

NN

N

DEFINE

calibration

N

type

N

RCS

N

of

NN

N

TARGT

target

N

PLATE

N

CYLINDER

N

OPTICAL

N

NN

N

RCS

N

NN

by

NN

N

NN

N

target

N

TARGET

pressing

N

Spheres produce a

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

OPTICAL SPHERE

calibration,

and

enter

model

its

Sphere:

Using

are

You

If

NOT

are

you

If

The Dierence

The top selection,

perfectly conducting sphere.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

The

OPTICAL SPHERE

geometric optics - in which the RF signal is treated as \optical rays" according to physical

called

4

PRIOR

the

for

of

required

principles

wavelength of

This is

region" when the following relationship between wavelength and sphere radius is true:

(2r4)>

Whereis wavelength and r is the radius of the sphere

NOTE: Radar Cross Section data for all target types except

optics.

Press

5.

Enter

6.

softkeys

a

gating

using

between Sphere

NNNNNNNNNNNNNNNNNNN

N

SPHERE

reection

energy

RF

the

\optical

the

10

.

5

MENU

(metric)

type

each

NN

N

NN

N

RF

.

using

select

selection

energy

NNNNNNNNNNNNNNNNNNNN

SPHERE

the

TARGET:

is

the

is in

are based on geometric

appropriate

SPHERE

used

best

behavior of

sphere's

dimension

when

\optical

that

The

.

target

always

sphere

approximates

it

calibration,

during

, computes the exact solution for the radar cross section of a

selection computes the radar cross section of the sphere based on

refraction. The

and

region"

dimensions

target:

of

the

and Optical

enough

large

is

the

of

sphere

the

of

Sphere

optical

N

.

the

light.

Antenna

and RCS

Calibration

3-19

RCS Calibration

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TARGET RADIUS

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TARGET HEIGHT

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TARGET WIDTH

Figure 3-3 shows the dimensions required for each type of target.

To specify dimensions in meters, terminate the value with

millimeters,use

4

k/m

5

.

4x15

.To specify dimensions in

Figure 3-3. Dimensions Required by Dierent Target Types

Note

On Dihedral and Plate targets, height and width are interchangeable. Trihedral

and sphere targets only require one dimension to be specied.

Desired)

Select

If

7.

RESPONSE

veraging

A

desired,

(if

turn

4

MENU

veraging

A

NNNNNNNNNNNNNNNNNNNNNNNNN

5

AVERAGING ON/restart

ON

NNNNNNNNNNNNNNNNNNNNNNNNN

set

and

it

factor.

Perform the Calibration

8. Make sure the RCS target is on the mount.

9.

10.

3-20

Press

4

gating

If

settings

Antenna and

CAL

is

aect

will

NNNNNNNNNNNNNNNNNNNNNNN

5

RCS CAL

ON,

the

not

RCS

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TARGET RESPONSE

select

can

you

calibration,

calibration.

the

aect

Calibration

whether

N

press

GATING

N

NN

to

NNNNNNNNNNNN

.

it

N

required value

the

n

[x1]]. Where

aect the

will

N

NN

N

YES

.

NN

N

If

GATING

N

or

F

.

n

is the desired

calibration.

N

NN

N

NO

example

o

T

selected,

is

make

press:

,

averaging

current

gating

RCS Calibration

11.

Measure the calibration target by pressing

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

MEASURE target name

. (This softkey displays

the name of the currently-selected target.)

At this time the receiver performs a response calibration on the target. This part of the

calibration reduces magnitude and phase discrepancies between the test and reference

channels (tracking errors).

12.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Press

TARGT RESP DONE

Optional Background Calibration

The next step is to measure the background. The background consists of the chamber

and mount without the RCS calibration target. This part of the calibration is an isolation

calibration. It reduces the eects of undesired chamber reections (clutter).

If you do not want to perform the background portion of the calibration, press

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

OMIT BACKGROUND

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

DONE RESP&BACK

. Now select one the of eight cal set registers to hold the

calibration data.

To perform the background calibration:

13. Remove the RCS target.

Press

N

MEASURE

NN

N

RESP&BACK

DONE

BACKGROUND

N

NN

N

NN

N

.

Now

select

one

the

of

eight

cal

set

registers

to

hold

the

14.

15.

N

calibration data.

proceed

Now

16.

used

you

If

remember

is

this

often

Updating

the

Once calibration

update the

1. Make

2.

Press:

3.

Press

background. T

sure the

4

5

CAL

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

DONE RESP&BACK

data:

store

can

You

a.

change

you

If

b.

set register

measurements.

single

change

to

the

normal

with

sweep

Continual

mode

sweep

RCS

mode

to

.

nd

back

the target

type needed

the

to

response

(earlier

actual

for

procedure),

this

in

measurements

Background

done

is

appropriate

N

NNNNNNNNNNNNNNNNNNNNNN

RCS CAL

change

you

if

,

this:

do

o

RCS

the

calibration

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

UPDATE BACKGROUND

RCS

mount,

ON.

is

or

background

the

changes

. Now select one the of eight cal set registers to hold the calibration

the original

updated

the

mounts

calibration

regularly

,

you

to

can

register

the

store the

which

updated

holds

calibration

to

. Then you can recall the register appropriate for each RCS mount.

,

version,

dierent

a

you

Most

.

should

cal

or:

Antenna

and RCS

Calibration

3-21

Network Analyzer Calibration

Network analyzer calibration features are documented in the

Programming Manual

.

HP 8530A Operating and

3-22

Antenna and

RCS

Calibration

Creating a Standard Gain Antenna Cal Denition

Creating a Standard Gain Antenna Denition

Introduction

If you use dierent standard gain antennas than those already dened, you must create a \cal

denition." Todothis, you must:

Create an ASCII text le on a computer.

Save the le to disc

Load the le into the HP 8530A.

This section explains how to create your own denitions.

Important Terms

Cal Denition A cal denition is an ASCII le you create using a text editor.

It contains theoretical or measured frequency and gain values

for one or more standard gain antennas.You can create the

le using any computer-based text editor which can save text

R



DOS

MS

an

to

le

the

save

can

then

le

be

loaded

can

into

contain

the

up

receiver

seven

to

plain

in

LIF

HP

or

the

from

\antenna

ASCII

format

disc).

The

.

disc

denitions

The

(which

le

denition

cal

."

antenna

Antenna

Supplied

The

HP

The

denition

receiver

\Loading

section.

this

Denition

8530A

AC_NAR1

(

can load

ou

Y

.

Cal Denition

the

Cal

not

is

Denition

shipped

is supplied

)

AC_NAR1

The

\antenna

contains

with

on the

or

,

into the

data

gain

denition."

up

denition

cal

a

Antenna

denition

cal

a

HP 8530A

specic

a

for

As

seven antenna

to

memory

in

RCS/Cal

you

". Details

standard

mentioned

denitions

.

Disc

,

create

AC_NAR1

on

gain

above

However

which

,

following

by

are

a

,

.

pre-dened

a

,

shipped

was

the

provided

cal

Required Hardware

A cal denition is a simple ASCII text le.You can create a cal denition using:

Any computer that can save ASCII les to MS-DOS compatible discs.

computer

Any

Interchange

that

ormat

F

can save

(LIF).

ASCII

les

to

discs

formatted

Hewlett-P

in

ackard

You MUST use a text editor that can save plain ASCII les!

called

is

denition

cal

the

with

instructions

end

the

at

Logical

an

in

of

Antenna

and RCS

Calibration

3-23

Creating a Standard Gain Antenna Cal Denition

Creating an Antenna Denition

A cal denition is composed of up to seven individual antenna denitions. Each antenna

denition applies to a specic standard gain antenna. Use the following instructions to create

an antenna denition.

Choosing the Number of Frequency Points to Dene

If the performance of the standard gain antenna is linear, you only need to dene a few

frequency points across the frequency band. Most standard gain antennas are not very linear,

so a greater number of frequency points are recommended. You can dene up to 201 frequency

points.

Covering a Wide Frequency Range

You can dene antenna denitions for up to seven standard gain antennas. This provides

continuous coverage over a wide frequency range. The calibration feature allows you to

measure up to seven antenna denitions for a single calibration.

alues

Determine

Required

Stimulus

V

Determine

recommends

antenna,

Start

Stop

even

frequency

Dierence

Number

and

start

The

Choosing

the exact

you

that

you

if

of

between

frequency

of

stop

Number

the

frequencies you

choose frequencies

make

only

standard.

your

of

standard.

your

frequency

.

points

of

you

P

frequencies

to

want

that

measurements

frequency

points

(the

already

know

oints

use

cover

at

the

in

the

single

from

antenna

entire

range

frequencies

increment).

published

the

denition.

your

of

.

data.

Hewlett-P

standard

ackard

The more points you use the more accurate the calibration will be. The limiting factor is

usually the published data for the standard antenna. The accuracy and resolution of the

standard gain antenna graphs or tables will be the limiting factor in calibration accuracy.

Determining

determine

To

(

number of points

the

Frequency

the

frequency

01).

increment,

Increment

divide

the

frequency

span

by

the

For example:

Start frequency

Stop frequency =

= 2 GHz

4GHz

gain

The frequency span is 2 GHz

Calibration

3-24

Antenna and

RCS

Creating a Standard Gain Antenna Cal Denition

Assume the standard gain antenna's graph or table provides 21 decipherable data values across

the 2 GHz frequency span:

Divide the frequency span by

number of points01

:

2x109/(2101) = 100 MHz

The rst frequency in your antenna denition is the start frequency (2 GHz in this example).

From there,20

additional

points exist, each spaced 100 MHz apart. The rst three frequencies

would be:

2,000,000,000 Hz

2,100,000,000 Hz

2,200,000,000 Hz

The last frequency point would be the stop frequency.

Determining Gain Values at Each Frequency Increment (Graph Format)

Next, you must determine the gain values at each frequency increment. Figure 3-4 shows a

typical graph-style data sheet for a standard gain antenna.

Choose

1.

respectively

the

Figure

start

.

and

3-4.

stop

Typical

frequencies

Standard

Examples

.

Gain

Antenna

shown

erformance

P

Figure

in

3-4

Antenna

Graph

are

and RCS

2

and

GHz,

4

Calibration

3-25

Creating a Standard Gain Antenna Cal Denition

2. Mark the graph at each frequency increment. In the example graph an increment frequency

of 100 MHz is used. You MUST use evenly-spaced frequency points, \Even Frequency

Increments" explains why.

3. On the graph for

your

standard antenna, determine the gain at each frequency increment.

Figure 3-4 shows example gain values for 21 frequencies spaced 100 MHz apart.

4. Write down each gain value in ascending order corresponding to the frequencies they

represent.

If Using Data in Table Format

Table 3-3 shows an example performance specication table:

Table 3-3. Example Standard Gain Antenna Performance Table

FREQ. (GHz) GAIN dB FREQ. (GHz) GAIN dB FREQ. (GHz) GAIN dB

12.4 13.82 14.3 15.02 16.2 16.21

12.5 13.88 14.4 15.08 16.3 16.28

12.6 13.95 14.5 15.14 16.4 16.34

12.7

12.8

12.9

13.0

13.1

13.2

13.3

13.4

13.5

13.6

13.7

13.8

14.01

14.07

14.14

14.21

14.27

14.33

14.40

14.46

14.52

14.58

14.65

14.71

14.6

14.7

14.8

14.9

15.0

15.1

15.2

15.3

15.4

15.5

15.6

15.7

15.20

15.26

15.33

15.39

15.45

15.52

15.58

15.65

15.71

15.77

15.83

15.89

16.5

16.6

16.7

16.8

16.9

17.0

17.1

17.2

17.3

17.4

17.5

17.6

16.41

16.46

16.52

16.59

16.65

16.71

16.76

16.81

16.87

16.93

16.99

17.05

13.9 14.77 15.8 15.95 17.7 17.11

14.0 14.84 15.9 16.02 17.8 17.18

14.1 14.90 16.0 16.09 17.9 17.24

14.2 14.96 16.1 16.15 18.0 17.30

The example graph has 57 evenly spaced frequency points that are 100 MHz apart. You will

simply

points,

enter

\Even

gain

these

Frequency

values into

Increments"

the

explains

ASCII

data

why

le

.

evenly-spaced

MUST

ou

Y

.

use

frequency

Even Frequency Increments

The frequency increments in the antenna denition must be evenly spaced.

the example on the next page you will see why: The lines

NOT

gain values

. Notice that these lines do

specify the frequency of

between

BEGIN

each gain value

If you look at

and

END

hold the

. Because

of this, the calibration feature must calculate the actual frequencies given the dened start

frequency, stop frequency and number of points.For this reason the antenna denition gain

.

can

in

values

choose

you

the

any

choose

antenna

frequency

frequencies

The

.

denition.

points

(When

wish.

you

the

in

used

calibrating,

A

values

When

must

you

calibration

have

not

do

Antenna and

3-26

represent

perform

be

can

be

to

RCS

evenly

actual

the

performed

the same

Calibration

spaced

calibration

any

at

frequencies

the

as

frequency

you

frequencies

cal

the

Creating a Standard Gain Antenna Cal Denition

receiver will interpolate between frequency points in the denition.) Remember, however, that

a

calibration

measurements

must contain

, the receiver

all

the frequencies required by your measurements. When

does not

interpolate between

calibration points

.

making

Required ASCII File Format

The ASCII le must follow the CITIle format supported by the HP 8530A. Figure 3-5 shows

an example le for the data in Figure 3-4. At rst the le looks complicated. However only

the items pointed out in Figure 3-5 are variable.To save time, start by editing an existing

calibration denition le. One is supplied on the

with the receiver. The le name of the le is

Antenna RCS/Cal Disc

AC_NAR1

.

, which was supplied

The cal denition shown in Figure 3-5 contains only one antenna denition. A cal denition

with

two

antenna denitions is shown in \Creating a Cal Denition with Multiple Antenna

Denitions", later in this chapter.

Figure

3-5.

Typical

Standard

Gain

Antenna

erformance

P

Antenna

Graph

and RCS

Calibration

3-27

Creating a Standard Gain Antenna Cal Denition

In-Depth Description of a Cal Denition

The example below is of a cal denition that contains one antenna denition. The top four

lines are the header for the entire le. These lines must only occur once, at the top of the le.

CITIFILE A.01.01

#NA VERSION HP8530A.01.00

#NAME ANTENNA_DEF

These three lines should be included exactly as shown. The rmware revision on line 2

\HP8530A.01.00" does

not

need to be changed if your HP 8530A has a later rmware revision.

Keeping line 2 exactly as shown above is acceptable. These lines are part of the le header.

#NA DEF_LABEL uWaveA.1

This line denes the title for the antenna calibration softkey.You can change the label

\uWaveA.1" to any label you want, up to the limit of ten characters. This line is part of the le

header.

STANDARD 1

#NA

the

this

,

.

line starts

This

number

\Creating

dening the

\1" should

Denition

a Cal

incremented

be

with

antenna

Multiple

denition.

and

3,

(2,

Antenna

When

on)

so

Denitions"

creating

each

for

several

successive

shows

an

antenna

example

denitions

denition.

of

STANDARD_LABEL

#NA

This

denes

the

\SASGH-1.10"

changed

be

label

the

FREQ

VAR

number

the

Enter

softkey

any

to

MAG

21

of

SASGH-1.10

label

you

label

reect

to

frequency

for

want,

the

points

this

type

antenna

a

to

up

and

the

at

denition.

maximum of

frequency

this

of

end

You

ten

range

line

change

can

characters

the

of

(where

the

It

.

standard

number

the

label

recommended

is

antenna.

gain

located

21 is

in this example). The rest of this line always stays the same.

DATA GAIN [1] DB

This line does not aect the antenna denition in any way, but we recommend you leave it in.

.)

(Future

rmware

revisions

require this

may

line

SEG LIST BEGIN

SEG 2000000000 4000000000 21

SEG LIST END

These three lines

dene the start frequency

, stop frequency

, and the number of points (again).

Frequencies must be expressed in Hertz. Never change the rst or third line.

BEGIN

1.70E1

1.714E1

1.725E1

.

3-28

Antenna and

RCS

Calibration

Creating a Standard Gain Antenna Cal Denition

.

1.855E1

1.858E1

1.86E1

END

The commands \BEGIN" and \END" must surround the gain values for each frequency. Enter

each gain value on a separate line. Gain values must be in ascending order corresponding to

the frequencies they represent.

Saving the Cal Denition File

Save the ASCII le to MS DOS or HP LIF disc.

Note

The lename must begin with the three characters:

(The two lettersACfollowed by an underscore character.)

Loading the Cal Denition into the HP 8530A

into

N

FAR

the

NN

N

CAL

select

that

N

NN

N

FIELD:

.

le:

N

on

the

N

HP

NN

N

KITS

the

N

NN

N

8530A's

N

disk.

that

desired

key

NN

N

RESPONSE

NN

N

ANTENNA

cal

N

NN

N

ANT.

N

drive

N

CAL

denition

N

CAL

N

Y

.

N

NN

N

DEF

contains

will

ou

N

,

and

see

the

press

name

your

cal

a

load

o

T

Insert

1.

Press

2.

all

Use

3.

Press

the

4

DISC

denition les

cal

the knob

4

5

CAL

NN

N

ANT.

the softkeys

denition

disc

N

5

LOAD

Notice

.

N

CAL

buttons

N

to

receiver

N

LOAD

you

antenna

N

AC_

will

N

FILE

chose

denition

display

N

NN

N

.

for

le

a

that cal

names

Measurement Tutorials

This chapter gives more in depth information on making measurements.Feature choices are

explained so you can customize measurements to suit your needs. The following subjects are

covered:

Chapter Contents

Angle Domain Measurement Tutorial

Step 1. Choose Internal, External, or HP-IB Triggering

Step

2.

3.

4.

5.

6.

Choose

Make

Measurement

a

Single

a

Single

which

Swept

a

Angle

Continual

or

arameters

P

Measurement

Frequency

Swept

or

Measurements

Measure

to

Angle

Measurement

4

External

HP

Frequency

Step

Triggering

85370A

Domain

1.Select

2.Choose

Single

Step

P

Sweep

Frequency

Sweep

Ramp

Position

Encoder

Tutorial

Internal Triggering

Single

a

mode

oint

(and

mode

List

mode

Operation

oint

P

how

or

to

Swept

increase

Measurement

Sweep measurements

Step

by a

factor of

six)

Step 3.Choose Single or Continual Measurements

Step 4.Choose which Parameters to Measure

Making Faster Frequency Domain Measurements

For information on common measurement tasks such as boresighting, averaging, nding depth

of

null,

and

so

on,

refer

Chapter

to

5.

Measurement

Tutorials

4-1

Angle Domain Measurement Tutorial

The following explains how you can customize angle domain measurements to suit your specic

needs.

Note

Step 1. Choose Internal, External, or HP-IB Triggering

Selecting HP-IB or TTL Trigger

The HP 8530A provides three trigger modes for use with antenna measurements. Press

STIMULUS

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TRIG SRC INTERNAL

N

NN

N

SRC

TRIG

N

NN

N

SRC

TRIG

If you have the HP 85370A Position Encoder, and have not congured the

receiver to use it, make the appropriate conguration settings as explained in

\HP 85370A Position Encoder Operation" before proceeding.

4

MENU

N

NN

N

HPIB

N

EXTERNAL

5

N

NN

NNNNNNNNNNNNNN

N

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

MORE

TRIGGER MODE

N

, then one of the following:

In Angle Domain, internal triggering is appropriate when using the

HP 85370A Position Encoder. If you

use External Trigger or HP-IB Trigger (described below). Internal

triggering

HP-IB

command

pulls

take

to

\TRIG

This

osition Encoder

P

negative-edge

input

controller's

trigger a

to

pulls

take

to

causes

Trigger

over

rear

the

data.

HPIB"

SRC

mode is

BNC. The

rear

the

data.

INCREMENT Trigger

measurement at

receiver

the

mode

this

In

.

HP-IB

the

STOP

panel

information

More

the

in

appropriate

trigger

This

.

TTL signal

trigger

STOP

panel

pulse

to

computer

a

to

bus

SWEEP

keyword

your

if

arrives

usually

each

SWEEP

do not

trigger

a

start

BNC

HP-IB

on

dictionary

system

starts

mode

the

at

comes

output. This

increment

BNC

use the Position Encoder,

itself automatically

controller

measurement.

(TTL)

line

triggering

does

a

rear

from

line (TTL)

must

HIGH

is

.

use

not

measurement

EVENT

panel

the

allows

The

.

angle

HIGH when

issue

The

when

supplied

HP

the

when

positioner

the

receiver

.

GET

a

receiver

ready

under

85370A

a

TRIGGER

ready

The annotationEappears on the left-hand side of the display if you are using external or HP-IB

triggering.

Step 2. Choose a Measurement Frequency

STIMULUS

Press

Step 3. Choose a Single Angle or Swept Angle Measurement

Next, select whether you want to measure a single angle or an angle scan (swept angle). An

angle sweep takes a number of data points across a range of angles

sweep

The following choices are available (under STIMULUS

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Single Angle

4-2

from090 degrees to +90 degrees

Measurement T

4

MENU

This mode is useful when boresighting an antenna when you are in the Angle

Domain.

angular

Single

utorials

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

5

FREQUENCY

Pressing

coordinates

display

the

,

Angle

of

N

NN

N

SINGLE

the

on

MEAS.

.

N

will

N

ANGLE

HP

show

,

NN

8530A

then

N

measures

a

enter

4

MENU

are

at

desired

the

5

) when using the Angle Domain.

single

a

to

360

0

that

line

CW

or example

.F

antenna

degrees

+360

represents

test

angle

the

frequency

.

, you might

.

If

value

.

Allowable

select

you

the

of

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Swept Angle

Angle Domain Measurement Tutorial

measured signal. Continual measurement mode (described below) and internal

triggering are suggested when using the Single Angle mode.

Pressing

keys to enter the desired start and stop angles.Use

choose the desired angular increment.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

SWEPT ANGLE

measures a range of angles. Use the

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

INCREMENT ANGLE

4

START

5

and

4

STOP

to

5

Note

Step 4. Choose Single or Continual Measurements

While in the Stimulus Menu, press

N

NN

N

SINGLE

N

NN

N

CONTINUAL

Remember that the HP 8530A does not control the positioner, and it does not

send commands to the positioner controller. If your positioner system allows

you to \program" a manual measurement from its front panel, set it for the

desired start, stop, and increment angle. Now enter these values into the

HP 8530A.

If your positioner system is completely manual, just enter start, stop, and

increment angles into the HP 8530A.

NNNNNNNNNNNNNN

MORE

and choose one of the following:

pattern

single

receiver

the

,

mode

this

In

measurement

the

measurements).

until

again,

Single

mode

done

pulses

ensures

are

prepares

N

is

are using

allows the receiver to make a measurement any time you move the positioner

forward past the selected starting angle.

or

mode

advantage

The

.

receiver

the

,

This

.

that

moving

just

the

recommended

the HP

is

The

press

you

recommended

is

goes

keeps

the

receiver

the

receiver

when

85370A P

antenna

measures

the

,

done

receiver

of

system

to

making

will

MEASUREMENT

whenever

using

\hold

into

will

positioner

make

osition Encoder

a

wait in

mode

mode"

responding

start

NN

N

goes

your

measurement

a

around.)

single

N

NN

receiver

single

from

not

another

N

SINGLE ANGLE

into

hold mode

4

RESTART

system

that,

is

and

sweep

N

In

.

measurement.

mode

Hold

until

.

5

external

in

is

the

when

ignores

to

measurements

Angle

any

triggers

false

accidentally

Pressing

measurement.

Domain,

N

stops

(it

N

NN

SINGLE

subsequent

N

SINGLE

is

trigger

measurement

(This

.

N

NN

N

or

if

or

,

N

NN

CONTINUAL

When

making

pressed

trigger

also

when

4

REST

you

NN

N

you

NN

is

ART

5

Note

Step 5. Choose which P

The receiver measures parameter that are displayed

measure parameters that

The number of parameters to be measured is selected by pressing

then one of the following softkeys:

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

SINGLE

PARAMETER

If you are using Continual measurements with external triggering, HP

recommends that you set \automatic IF correction" to manual mode. Refer to

more

\External

Triggering",

arameters to Measure

are not

causes the receiver to measure and display one parameter.

Choose

4

P

later

displayed on the screen.

ARAM

the

5

3

desired

or

,

4

ARAM

P

parameter

chapter

this

in

, for

on the screen. The receiver

by

.

5

4

information.

4

DISPLAY

pressing

does not

NNNNNNNNNNNNNNNNNNNNNNNNN

NNNNNN

5

DISPLAY MODE

4

ARAM

P

Measurement

,

5

1

NNNNNNN

4

ARAM

P

Tutorials

,

5

2

4-3

Angle Domain Measurement Tutorial

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TWO PARAMETER

causes the receiver to measure and display PARAM 1 and

PARAM 2 for the active channel.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

THREE PARAMETER

causes the receiver to measure and display PARAM 1,

PARAM 2, and PARAM 3 for the active channel.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

FOUR PARAMETER

causes the receiver to measure and display all four parameters

for the active channel.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

DUAL CHANNEL

causes the receiver to measure and display one parameter (of

your choice) in each channel. For each channel, choose the

desired parameter by pressing

4

PARAM 4

5

keys.

4

PARAM 1

5,4

PARAM 2

5,4

PARAM 3

5

Step 6. Make a Swept Measurement

Making Swept Measurements Using Single Sweep Mode

1. If your positioner controller requires it, enter the start, stop, and increment angle using its

front panel controls. If you can move the antenna using a simple knob, skip this step.

,or

Enter

2.

3.

Press:

Move

4.

POSITIONER

Move

5.

measure

o

T

6.

Press

Move

7.

Move

8.

Making

stop

start,

STIMULUS

positioner

the

ANGLE

antenna

the

another

N

NN

N

SINGLE

positioner

the

antenna

the

Swept

increment

and

,

N

5

about

the

N

MORE

3

stop



it

4

MENU

FORWARD

to

sweep

MEASUREMENT

or



3

about

stop

the

to

Measurements

NN

N

SINGLE

front

in

is

angle

front

in

angle

Using

angles

NN

N

ready

.

4

REST

.

the

into

N

NN

simply

or

start

the

of

make

to

again.

5

ART

start

the

of

Continual

receiver

the

.

MEASUREMENT

press

When

.

angle

measurement.

.

angle

Sweep

Mode

the

receiver

4

REST

displays

ART

.

5

MOVE

1. If your positioner controller requires it, enter the start, stop, and increment angle using its

front panel controls. If you can move the antenna using a simple knob, skip this step.

2. Enter start, stop, and increment angles into the receiver.

3. Move the positioner about 3in front of

ready

is

stop

it

angle

POSITIONER

Move

4.

the

ANGLE

antenna

FORWARD

the

to

the start angle. When the receiver displays

measurement.

the

make

to

.

MOVE

To measure another sweep

5. Move the positioner about 3in front of the start angle

6. Move the antenna to the stop angle

Measurement T

4-4

utorials

.

External Triggering

Before You Use External Trigger Modes

Read this if you are using Continual or Number of Groups mode, and the receiver is externally

triggered:

Before you select an external trigger mode, you should disable the automatic IF Correction

feature of the HP 8530A. (Remember do this

of Groups mode, and the receiver is externally triggered). IF Correction is a feature that

periodically calibrates the IF stages of the receiver. When this \invisible" calibration

occurs, there is a small interruption in the measurement. In internal triggering, this delay

is not a problem. However, in external triggering applications (such as angle scan antenna

measurements), this delay can disrupt the measurement. You can avoid this problem in either

of the following ways:

You can use single mode by pressing: STIMULUS

only

if you are using Continual or Number

4

MENU

NNNNNNNNNNNNNN

5

MORE

NNNNNNNNNNNNNNNNNNNN

SINGLE

.

or

You can turn automatic IF correction OFF by pressing:

NN

N

IF

If

perform

N

RESET

Note

Using

TTL or HP-IB triggering can be modied to suit your needs. By default triggering works as

follows:

If you are displaying a single parameter, each trigger causes the receiver to:

1. Measure the selected parameter at the current angle or frequency.

2.

N

NN

CORRECT

select

you

N

IF

External Trigger

in

If

analyzer

the

by the operator or computer controller

N

NN

N

MANUAL

N

IF

N

a

RESET

N

NN

N

CORRECTION

If

the

After

leave

Frequency

NN

N

NN

N

CORRECT

N

NN

N

IF

N

NN

N

sweep

Correction

IF

making

external

Domain,

advances

.

N

NN

N

MANUAL

N

NN

N

CORRECTION

N

causes

mode

is

Continual

trigger

Modes

the

internal

its

the

set

feature

N

you

,

N

command

receiver

to Single

measurements

mode

receiver

increment

get

will

before

to

(STIMULUS

to

set

remember

,

advances

.

greatest

perform

UTO

A

angle

starting

.

if

,

to

the

to

counter

4

SYSTEM

IF

an

4

MENU

you

turn

N

5

IF CORRECTION

accuracy

gain

measurement.

each

correction.

IF

N

NN

N

5

MORE

back

go

correction

IF

frequency.

positioner

The

.

N

NN

N

SINGLE

single

to

N

If

you

if

N

back

in

N

you

,

sweep

to

Angle

must be

can

mode

UTO

A

Domain,

moved

leave

or

,

.

3. Wait for another trigger (see Figure 4-1).

Measurement

Tutorials

4-5

External Triggering

Figure 4-1. Default External Triggering Flowchart (single parameter)

If you are displaying four parameters, each trigger causes the receiver to:

1. Measure all four parameters at the current angle or frequency.

in Frequency

2. If

the analyzer

the

by

ait

W

3.

operator or

another

for

Figure

Domain, the

advances its

computer controller

trigger

Default

4-2.

Advanced Triggering F

receiver advances

internal increment

.

Figure

(see

External

4-1

Triggering

eatures

The Trigger menu softkeys (under STIMULUS

triggering exibility

. They instruct the receiver to wait for a trigger before measuring specic

angle counter

).

4

MENU

the

to

Flowchart

NNNNNNNNNNNNN

5

MORE

frequency

The

.

(four

N

NNNNNNNNNNNNN

NNNNNNNNNNNNNNNNNNNNNNNNN

TRIGGER MODE

Angle

in

If

.

must

parameters)

) provide greater

Domain,

moved

be

parameters or before it advances to the next stimulus point. (This is the next angle in Angle

Domain, or the next frequency in Frequency Domain.)

Here is a description of each custom triggering softkey:

NN

N

NN

N

NN

N

TRIGGER:

Measurement T

4-6

STIMULUS

utorials

turned

When

receiver

to

ON

wait

(underlined),

trigger

a

for

N

NN

N

TRIGGER:

before

N

moving

N

NN

N

STIMULUS

to

N

forces

the

stimulus

NN

N

External Triggering

point.

are not compatible with the HP 8530A System Bus.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TRIGGER: PARAM 1

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TRIGGER: PARAM 2

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TRIGGER: PARAM 3

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TRIGGER: PARAM 4

Each of these softkeys is an ON/OFF toggle, and you can turn them on or o in any

combination. When a softkey title is underlined, that function is ON. When the title is not

underlined, the function is OFF.

How these Functions Work when One Parameter is Being Measured

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

The

TRIGGER: STIMULUS

functions

N

TRIGGER:

or

F

N

TRIGGER:

N

TRIGGER:

these

work dierently

N

NN

N

example

NN

N

PARAM

,

N

PARAM

N

NN

N

PARAM

parameters

N

NN

N

softkey

viewing

are

you

if

N

NN

N

softkey

2

N

NN

N

1

are

N

,

TRIGGER:

not

When turned ON, the receiver to waits for a trigger pulse

before measuring parameter 1.

When turned ON, the receiver to waits for a trigger pulse

before measuring parameter 2.

When turned ON, the receiver waits for a trigger pulse before

measuring parameter 3.

When turned ON, the receiver waits for a trigger pulse before

measuring parameter 4.

function can always be used. However,the

you

If

.

that

for

will

N

NN

N

measured.

being

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TRIGGER: STIMULUS

displaying

only

are

The

N

3

will

as

2,

other

N

and

,

parameter

work.

NN

N

PARAM

allows you to use RF sources that

(measuring)

eect

an

have

Figure

shown

N

TRIGGER:

in

parameter-related

NN

N

NN

N

PARAM

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TRIGGER: PARAM

the

only

the

ignored,

,

because

parameter

one

triggering.

on

only

,

4-3

softkeys

N

NN

N

4

will

be

Figure 4-3. Custom External Triggering Flowchart (one parameter)

How these Functions Work when Four Parameters are Being Measured

parameters

four

If

each

of

NN

N

TRIGGER:

N

softkey

N

NN

N

PARAM

N

(

TRIGGER:

N

4

are

N

)

N

being

NN

N

before

measured, the

NN

N

PARAM

measures them.

it

N

,

1

TRIGGER:

N

receiver

N

NN

N

Refer

N

PARAM

will

N

to

N

check

N

NN

N

,

2

Figure

ON/OFF

the

N

TRIGGER:

.

4-4

N

NN

If

condition

N

PARAM

N

NN

N

TRIGGER:

Measurement

N

NN

N

3

N

and

,

N

NN

N

PARAM

N

Tutorials

N

1

4-7

External Triggering

is on, for example, the receiver will wait for a trigger before it measures parameter 1. This

process repeats for each parameter.

EXAMPLE 1

TRIGGER: STIMULUS ON

TRIGGER: PARAM 1 OFF

TRIGGER: PARAM 2 OFF

TRIGGER: PARAM 3 OFF

TRIGGER: PARAM 4 OFF

In this example, the receiver will:

1. In Angle Domain: Wait for one trigger before

internally

selecting the start angle (or the

next angle in the measurement). This only aects internal receiver circuitry, it does not

move the positioner!

In Frequency Domain: Wait for one trigger before it commands the RF source (and LO

source, if used) to switch to the start frequency (or the next frequency in the measurement).

2. When the trigger arrives:

In Angle Domain: The receiver internally selects the start angle, or the next angle in the

measurement.

used)

can

that

source

,if

trigger

not

is

to

the

o

In

switch

receiver

The

3.

process

This

4.

that

Note

Record

The

Increment output

most common

controlled

stimulus

EXAMPLE

TRIGGER:

Domain:

start

the

to

measures

repeats

one

only

by the

HP 8530.

point, then

2

STIMULUS

frequency

for

trigger

for

use

have the

receiver

The

,

four

all

successive

each

required

is

a

from

TRIGGER:

receiver

OFF

commands

or

parameters

per

positioner

STIMULUS

make

frequency

.

trigger

stimulus

controller

the

the RF

source (and

the

in

.

point.

Thus

.

using

when

is

allows

you

measurement.

LO source

measurement.

receiver

the

,

source

RF

an

the

move

to

TRIGGER: PARAM 1 ON

TRIGGER: PARAM 2 OFF

TRIGGER: PARAM 3 OFF

TRIGGER: PARAM 4 OFF

to

the

In this example, the receiver will:

In Angle

1.

This

Domain:

only aects

Internally

internal

occurs before the trigger arrives

select

receiver

circuitry

.

move

not

does

it

,

the

(or

angle

start

the

In Frequency Domain: Commands the RF source (and LO source

in the

angle

the

, if used) to switch to the

measurement).

Notice

start frequency (or the next frequency in the measurement). Notice that this occurs before

the trigger arrives

.

2. Wait for a trigger pulse before measuring parameter 1.

3. When the trigger arrives, the receiver will measure

the

parameter

This

4.

Measurement T

4-8

other

process

three

1.

then

\wait

utorials

for

repeats

trigger"

a

each

for

softkeys

successive

are

OFF

trigger

all four

they

,

.

parameters. Why? Since

will be

measured

along

with

that this

External Triggering

This conguration is the default external trigger setup, and will work if using the Record

Increment from a positioner controller.

EXAMPLE 3:

TRIGGER: STIMULUS OFF

TRIGGER: PARAM 1 ON

TRIGGER: PARAM 2 OFF

TRIGGER: PARAM 3 ON

TRIGGER: PARAM 4 OFF

In this example, the receiver will:

1. In Angle Domain: Internally select the start angle (or the next angle in the measurement).

This only aects internal receiver circuitry, it does not move the positioner! Notice that this

occurs before the trigger arrives.

In Frequency Domain: Commands the RF source (and LO source, if used) to switch to the

start frequency (or the next frequency in the measurement). Notice that this occurs before

the trigger arrives.

2. Wait for a trigger pulse before measuring parameter 1.

stop

will

it

then

2,

3.

4.

When

wait

When

the

for

the

trigger

another

second

arrives

trigger

the receiver

,

.

arrives

,

will measure

receiver

the

will

measure

parameters 1

and

parameters

3

and

4.

and

This

5.

setup

This

external

Note

process

could

hardware

repeats

then

if

used

be

measuring

are

If

before

you

receiver will

were in

will not

the

properly

the Internal

work properly

actual

.

successive

each

for

measure

to

need

you

the

External

in

never

Trigger

wait

Trigger

in

Internal Trigger

second

any

for

mode

this

mode (

trigger

parameters

two

parameters

two

and

,

mode

triggers

However

.

situation.

N

NN

TRIG

.

N

SRC

you

Instead,

the

,

Encoder

The

N

NN

N

INTERNAL

.

turn

N

then

,

HP

N

all

it

N

will

N

switch

softkeys

ve

\free

85370A

requires

N

NN

or it

)

inputs

run"

osition

P

that

will

OFF

as

you

not

using

the

,

it

if

Encoder

select

operate

Measurement

Tutorials

4-9

External Triggering

4-10

Figure

Measurement T

4-4. Custom

utorials

External

Triggering

Flowchart

(four

parameters)

HP 85370A Position Encoder Operation

Introduction

This chapter explains how to operate the HP 8530A softkeys that control the HP 85370A

Position Encoder. Remember, the HP 85370A only works when the HP 8530A is equipped with

option 005, \Position Encoder Interface." This chapter assumes that the positioner encoder

is installed and congured as explained in the

Service Manual

.

HP 85370A Position Encoder Installation and

Position Encoder Softkeys

o access

T

the P

osition

Figure

Encoder

4-5.

osition

P

menus

press:

,

Encoder

NNNNNNNNNNNNNNNNN

4

DOMAIN

5

ANGLE

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

STIMULUS

4

MENU

5

ENCODER FUNCTIONS

The position encoder softkeys are listed below:

N

NN

N

NNNNNNNNNNNNNNNNNNNNNNNNN

encoder

N

NN

N

,

AXIS B

NNNNNNN

N

and

NN

N

NNNNNNNN

osition

P

N

NN

N

AXIS A

NNNNNNNNNNNNNN

BORESIGHT ANGLE

NNNNNNNNNNNNNNNNNNNNNNNNN

NNN

SAVE OFFSET

operation

N

,or

NNNNNNNNNNNNNNNNNNNNNNNNN

NNN

CLEAR OFFSET

N

NN

N

AXIS C

functions:

N

NN

N

NNNNNNNNNN

Position encoder conguration functions (press

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

SYNCHRO SINGLE

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

POL

ANG

N

NN

N

DISPLY

ANG

to

0

N

NN

N

ON/MOVE

360

N

NNNNNNNNNNNNNN

or

DUAL

NNNNNNNNNNNNNNNNNNNN

or

+/-180

N

or

N

OFF

N

NN

N

(option

NNNNNNNNNNNNNN

MORE

Softkeys

005)

to see these functions):

Measurement

Tutorials

4-11

HP 85370A Position Encoder Operation

Conguration Functions

Single and Dual Synchro

The single and dual synchro control softkeys are:

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

SYNCHRO SINGLE

Selects single synchro (1:1) operation. This is also referred to as coarse

resolution mode. This setting is applied independently to each axis.

NNNNNNNNNNNNN

N

DUAL

Selects dual synchro (1:1 and 36:1) operation. This is also referred to as

ne resolution mode. This setting is applied independently to each axis.

Selecting single and dual synchro mode for any axis.

independently for each axis.

N

1.

Press:

4

DOMAIN

STIMULUS

2.

Select the desired axis by pressing:

Display

angle

NN

N

POL

NNNNNNNNNNNNNN

MORE

the

display

N

0

N

to

N

3.

Press:

Repeat

4.

Angle

The

N

ANG

NNNNNNNNNNNNNNNN

5

ANGLE

4

MENU

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

5

ENCODER FUNCTIONS

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

SYNCHRO SINGLE

steps

two

last

Modes

softkeys

mode

N

NN

N

360

Causes

for

each

are:

the

or

HP

NNNNNNNNNNNNNNNNNNNN

AXIS A

NNNNNNNNNNNNNN

DUAL

.

axis

8530A

NNNNNNNNNNNNNNNNNNNN

,

AXIS B

and the

position

360format.

N

NN

+/-180

N

NN

N

DISPLY

ANG

8530A and

HP

180

If

the



format.

softkey

angle

to

.

performs

display

dierent

a

already

is

position

two

Causes

6

N

ON/MOVE

This

N

NN

N

1.

readout

positions

position

the

functions:

turned

Note: Select single and dual settings

NNNNNNNNNNNNNNNNNNNN

,or

AXIS C

angles

moves

are ve

the

dierent

on

the

encoder

ON,

display

this

to

softkey

There

.

display

0

in

angle

to

NNNNNNNNNNN

OFF

4-12

Measurement T

2. It turns the angle readout ON if it was previously OFF. This aects

the HP 8530A display.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

From the Encoder More menu, press

ANG DISPLY ON/MOVE

position of the angle readout changes. There are ve possible

5

box,

until

positions

lower

softkeys

if

menus disappear

.

right-hand

are being

corner

, and you will be able to see the angle readout.

the

of

One

Turns the HP 8530A

above the

the

is

screen.

Press

positions

of

displayed.

angle display OFF

Time/Date

position cannot

This

4

PRIOR

MENU

.

utorials

.The

the

in

seen

be

the softkey

Agilent 8530A User's Guide

Specifications and Main Features

Frequently Asked Questions

User Manual

Guide to this Manual

Getting Acquainted with the HP 8530A Receiver

Manual Measurement Examples

Antenna and RCS Calibration

Measurement Tutorials