HP 8530A User Manual

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

Programming

arning

W

Caution

,

warranty

,

Regulatory

arranty

and

,

Manual

Before

grounded

socket

Any

outside

can

Before this instrument is switched on,

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

the

,

regulatory

.

instrument

this

through

outlet

interruption

the instrument,

result in

instrument

personal injury

information

the

provided

of

the

when

Information

supplied

is

make

,

is switched

protective conductor

with protective

the protective

or disconnection

power

ac

on

(grounding) conductor

.

make sure its primary power circuitry

cable

8530A

HP

the

in

it

sure

the

of

earth contact.

of the

plugged

is

protective earth

in.

has

ac

power

Operating

properly

been

cable

inside

,

and

to

or

terminal

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

.

Instrument

results

pressing

by

0-1.

and

485

5

key.

pressing

information

4

5

through

0

4

5

(giga or nano),

G/n

and

495

4

PRIOR

4

ENTRY

Figure

Display

1.

display

The

display

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

up

Go

Turn

shows

softkeys

Block

block allows you to:

4

x1

one

the

OFF

measurement

.

5

(basic units),

softkey

of

level

active

4

BACKSPACE

menus by

function

the keypad

Overview

messages.

4

5,4

MENU

.

5

+/-

5

.

5

9

keys, or using the rotary knob.

OFF

It also

.

4

5

M/u

shows the

(mega or micro),

names of

4

5

(kilo

k/m

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

Menus

4

5

CAL

4

DOMAIN

4

DISPLAY

4

MARKER

switch

data

controls

parallel

features

displayed

9.

Contains

10. AC power switch

This

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

major

three

Angle

applies

of

or

,

functions

dierent

power

C

A

pathways

they

,

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

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

SAVE

registers (for later recall).

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

5

and

4

RECALL

5

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

4

USER PRESET

time you turn power ON or press

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

Domain).

Frequency

Trigger

85370A

HP

arameter Block

P

13.

block

This

4

P

signal

very

to

signals

ARAM

are

accurate

measure

4

on

5

levels

(single

type

measurement

of

List

mode

P

selects

select

5

measured,

measurement

any

a1,

the

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

RF

for

sweep

mode

(internal,

osition

which

dierent

and

the

of

b1,

a2,

LO

and

continuous

,

points

setup

external,

Encoder

8530A

HP

\ratioed"

then

results

input

four

b2

or

4

USER PRESET

sources

(in

.

or

controls

inputs

measurements

mathematically

are

Softkey

.

lines

input

.

sweeps

Frequency

HP-IB).

.

without

.)

lines

5

the settings stored in register 8 are retrieved.

ramp sweep

,

Domain),

measure

to

.

menus

ratioing. (This

the

.

\Ratio"

divided

under

sweep,

,step

increment angle

or

that

This

.

4

main keys

means

together

block's

this

feature allows

and more).

(in Angle

through

5

1

ARAM

P

and reference

test

a

method provides

4

MENU

key

5

you to

allows

check the

you

14. Auxiliary Menu

This area contains three control keys:

print

to

4

COPY

4

DISC

disc-related

4

SYSTEM

are controlled are: phase lock, IF calibration,

(used when more than one source is connected to

service menus that are used when troubleshooting the instrument.

15. Format Block

This block

log format.

vi

allows

5

allows

5

you

the

use

to

you

to

.

select

functions

5

contains instrument conguration functions

allows

plot

or

disc

dierent

measurement results

the

drive

to save

display

or

power leveling, and multiple-source setup

formats

.

format

,

les

load

Examples of the type of functions that

.

the HP 8530A). The system key also has

as

such

discs

Cartesian

or

polar

perform

and

,

other

linear

in

,

or

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

8530A

HP

the

with

the

of

Examples

in

front

of

.

HP

the

panel

the HP

8530A,

Figure

Getting

Chapter

8530A

Chapter

Chapter 2 shows very basic antenna and RCS measurement examples.

Chapter 3. Calibration

Chapter

Chapter 4. Measurement Tutorials

This chapter gives more in-depth information on making measurements

explained

how to use

1.

quick

provides

1

features

2.

describes

3

so you can customize measurements to suit your needs

the HP 85370A P

a

.

Manual Measurement

the

0-2. Sections

cquainted

A

overview

calibration

osition Encoder

features

User's

8530A

controls

Guide

receiver

display

,

how

and

. 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.

utomated

Making

Chapter

how

receiver

point.)

Chapter

This

How

What

How

Appendix

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.

Appendix

Lists

plotters, and monitors

8.

explains

8

the

use

to

automatically

to

9.

to

explains:

solve

do

solve

A,

B

chapter

compatible

ast

F

Case

In

common

when

basic

Optimizing

Compatible

,

RF

A

measure

to

how

Multiplexing.

IF

switch

of

operation

specic

hardware

LO

and

.

between

Diculty

error

problems

Dynamic

Instruments

sources,

Measurements

5,000 points

up to

IF

ast

(F

dierent

problems

messages

frequency

are

.

Range

per second

multiplexing

input

displayed

and P

converters

eripherals

similar

is

ratios

the

on

positioner

,

using F

each

at

screen.

ast

ast CW

F

to

angle

controllers

mode

CW

,but

frequency

or

printers

,

and

,

allows

the

,

Appendix C, Supplies

Lists commonly-needed supplies (plotter pens

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

Connector

,

Appendix

Explains

D

connector

care

techniques

ccessories, After-Sale Options

,A

, discs) and after-purchase options (time

procedures

.

Care

and

, paper

cleaning

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

Installation

Troubleshooting

Performance

Typeface

Bold

Italics

Computer

Display

4

Front P

NNNNNNNNNNNNNNNNNNNNNNNN

NNNNN

Soft Keys

Service

On-Site

anel Keys

key/softkey

.

order

Service

tests

Conventions

5

and

Manual

specications

and

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

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

the

Getting Acquainted

1-2

with

HP

8530A

Receiver

Basic

over a

1-1.

wide

capability

Figure

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.

speed

linearity

data acquisition

Excellent

High

Sensitivity

Antenna

dynamic

.

Measurement

.

range

Block

Diagram

The foundation of good system performance

measure very small signals

noise. When used with the HP 85310A frequency

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

greater

with

and

quickly

,

. Excellent sensitivity

accuracy

and high speed is sensitivity|the ability to

is only possible in systems that have very low

converter, the HP 8530 can measure signals

.

Getting

Acquainted with

the

HP

8530A

Receiver

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.

the

Getting Acquainted

1-4

with

HP

8530A

Receiver

Measurement Features

The major

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.

Frequency

Allows

frequencies

Domain

when

single

operational

Domain

measure antenna

to

you

Frequency

.

,

mode

measuring

frequency

x-axis

the

frequency

choose

or

,

features of the HP 8530A are listed below:

Domain

phase

must be

performance

Internal

.

be

can

Frequency

made

used

List

at

triggering

as

sweep

Domain

of the

but

,

from Ramp

Angle

Figure

magnitude and

measurements

display

external triggering

1-2.

frequency

is

Step

,

or

single

a

well.

across

modes

or

one

.

angle

commonly

is

can

ou

Y

.

more

Frequency

In

used

measure

a

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

measurements

isolation

is used

example a

then

which

inputs to

5

calibration

if you

want to

network

use a2,

mathematically

Also

calibration

,

ou

Y

a1.

select

,

response

the

,

assume you

perform the

In this

could

,

4

PARAM 1

frequency

and

by

also

is

(or

accurate

reected

,

keys

4

PARAM 4

gain

antenna.

gain

crosstalk.

signal

provided.

.

output).

measurements.

signals.

signal

described

5

.") F

This

example

or

F

ou would

Y

into

below

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

or example

Antenna

calibrating

reduces

\network

A

make

the

calibration

coupler

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

carry

for

Selectable Input Ratios

4

PARAM 1

measure.

(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.

calibration provides

antenna

an

could

to

The

,

4

5

measure

input

PARAM 3

against

calibration

\P

your range

measurement errors

analyzer"

network

impedance

is

,

test

your

5

analyzer-type

of

you

so

required

assume you

signals.

measurement.

,

4

PARAM 2

(\PARAM" is short for \parameter

accurate

a

caused

measurements

input

very

make

the

reference

the

ARAM"

, and

5

standard

by

feature

to

want

measure

analyzer

directional

b2

or

b1,

together

ratio

divides

to

the

Getting Acquainted

1-6

with

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

.

erformance

Measure

Normalize

The

amplitude)

reference

be

will

Remote

HP

The

HP-IB

modes

Data

HP

The

Antenna patterns

Frequency response measurements

Time domain

Radar Cross Section (RCS) frequency and time domain measurements

HP

The

Display F

You can select logarithmic or linear

display format (Cartesian only). Y

the screen.

P

Trace

.

dB

0

to

point.

relative

Programming

8530A

All

.

operation

of

Presentation

8530A

When

the

to

can be

front panel

can

allows

ormats

function

ou

Y

peak.

and current

show measurement

you

Relative

sets

then

can

is

data

controlled

features

Features

print

to

use

saved,

remotely

are

instrument or

ou can display

to

(the

lobe

main

the

of

peak

the

magnitude

trace

view

markers

printed,

supported.

results right

plot measurement

or

magnitude display formats (Cartesian or polar), or phase

to

output

or

computer

query

can

status

display

on its

results

one,two, or four parameters simultaneously on

from

plotted,

any

ou

Y

system

to

that

the

.

Main

the

of

eak

P

the

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

presentation.

measurement

Alternatively

channels

,

(more

you

on

display

can

channels

one

explained

is

parameter from

later).

Getting

Acquainted with

each

of

independent

the

HP

the

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

frequency

accuracy

011

allows

adds

you

or

in

high-performance

measure

to

optional

arameter

S-P

time

the

domains

network

vector

transmission

.

measurements

network

These

analysis

reection

and

advanced

.

features

properties

calibration

(HP

of

features

8510C

microwave

operation).

provide

devices

optimum

in

the

Getting Acquainted

1-8

with

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

supported,

are

MS-DOS

with

Hewlett-P

with

.

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

measurement

MHz

supply

the

LO

Interconnect"

signal.

IF

LO

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

such

,

and

external

8530A

frequency

tunes

that

as

digital tuning

the HP

oset by

is

HP 85310A,

the

LO

data is

8511A/B.

sources with

The local

20 MHz.

require another

sent

oscillator mixes

The result

HP-IB commands

is the

source

to

sent

the

20

over

the

Getting Acquainted

1-10

with

HP

8530A

Receiver

Figure

1-5.

HP

8530A

Measurement

Data

Flow

Diagram

In

choose

two

are

dierent

can

ou

Y

.

identical

features

Getting

then

digital

turned

Acquainted with

can

There

.

have

Analog:

you

sections:

main

two

has

8530

HP

The

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

any format

results

disc

,

and

or

the

external

Channel

displays

then

plotter,

Channel 1

view the dierent results

time.

in

computer

ou

Y

2.

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

.Y

main section,

rst

the

analog circuitry

results

output

processing paths

ON

the

in the

the

HP

two

8530A

detects

to printer

called

,

channels

Receiver

,

and

,

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

REDEFINE

remaining

N

NN

example

or

lock

N

NN

N

PARAMETERS

inputs

N

can

assume

,

reference

N

NN

N

be

NN

N

PHASE

used

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

one

input

The

these

When

Getting Acquainted

1-12

selector

are

sends

measured

with

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

periodically with

calibration

user

is done

. The

an automatic

features

,and

calibration coecients

self-calibration. This

cannot be

controlled

used

in

independent

to

sent

are

data

the

orm

F

These

.

in

1

is

of

Channel

or

channel

raw

1

.

one

holds

described

if

format.

1

features

Channel

data

you

Time

2,

If

2.

ast CW

F

If

.

array

data

X,Y

the

in

using

are

Domain,

and select

F

the

Similarly

.

pair

8530A

HP

the

\Other

the

mode

CW

ast

is

mode

Channel

,

special

a

in

eyword

K

CW

ast

F

Data

display

Frequency

format,

utomated

not

is

being

mode

identical

ratioed

inputs

the

Next,

Channel

Now

in

used,

averaged

Data

compressed data

Dictionary

The

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

results

Processing"

and

Domain

same device

More information on the \other"

Operation," later in this guide

1

selected

any

,

data

,

use

Channel

data

\arrays"

buer

be

to

on. F

so

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

are

Channel

and

averaging

the

to

sent

is

averaged

1

is stored

are data

format called

ast CW

The F

.

contains up

processed

shown in

steps

example

or

, and display the results simultaneously

together

processing

data

2

is

CW

ast

F

data

in the

holding locations

to 100,000

and

,

Channel

buer can

shown

Figure

can

you

.

and

paths

performed

buer

stored

is

\Form

X,Y data

in dierent

1-5

select

data processing steps is provided in \Standard A

on

from

in

raw

2

A

.

1." This

data

send

and

,

Time

the

data

pairs

include

copies

.

Channel

active

the

Channel

array

data

array

format

computer

to

in

ways

Domain

.

calibration,

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

data side-by-side

2

ou can

view the

Domain,

(dual channel

P

data separately

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;

2.

the keyword

start,

feature

a stimulus

If

If you

.

,

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.

STIMULUS This

These

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

power

RF

you can

TRIGGER jack

.

levels

trigger

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

predened

contains

ARAMETER

P

ARAMETER

P

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

RESPONSE

Each major control block has functions that are not mentioned here

and 9 in the

Many features are described in this User's Guide

The

(b1/a1),

measurement

data

most

Antenna

any

N

SERVICE

can select logarithmic magnitude (

phase (

magnitude (

The

Functions

(Normalization

measure other

HP 8530A Operating and Programming Manual

4

ARAM

P

the

from

errors

Under

two inputs

NN

N

response block

N

NN

4

PHASE

N

1

under

block

the

for

reference

the

ou

Y

desire

N

4

P

range

can

.

N

SERVICE

let

(b1/a2),

5

2

mode

and

test

caused

N

a1

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

LINEAR ON POLAR

by

est.

T

you

N

NN

N

through

5

), polar logarithmic magnitude (

keys

the MENU

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

parts of the trace relative to the peak.)

the

(b2/a1),

5

3

ARAM

mathematically

to

receiver

ou

Y

NN

N

you

key

is

shows

also

N

b1

.

any

look

N

NN

softkeys

the

turn

antennas

and

,

redene

can

N

NN

4

LOG MAG

, located under the FORMAT MENU key)

set

to

you

let

.

input

4

and

ARAM

P

Ratioed

actual

the

parameter

the

of

any

at

.

5

), linear magnitude (

4

POLAR MAG

display

scale

averaging

on

. Refer to Chapter 6, 7, 8,

for descriptions of these features

(b1/a1).

5

4

ratio

measurements

performance

input

single

5

), and polar linear

and

ARAM

P

The

(divide)

reduce

of

ratio

to

keys

the

using

4

LIN MAG

reference

normalization.

the

line.

4

keys

ratio

5

1

normal

the

5

),

.

the

Getting Acquainted

1-16

with

HP

8530A

Receiver

ENTRY Block

Front Panel Overview

specic

a

supply

degrees

in

K

the

entire

values

units

be

steps

eypad

and

supply

necessary

is

it

cases

some

In

digit

10

The

frequency

digits

4

k/m

entering

to

the

Changing

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."

Enter

2.

the

a

3. T

.

terminate

(kilo/milli)

5

data

keys

9

and

8

Values

new value

the

number

terminator

erminate the

.

value

the

4

and

x1

the

with

allow values

Using the

If you

key

make

, you

entry with the appropriate units

to

keypad

with

(basic

5

keypad, the

using

a

must

is

the

units:

to be

numeric

mistake

re-enter

numeric

to

used

appropriate

dBm,

,

dB

knob can

changed

Numeric

decimal,

,

press

,

the

these

.

used

.

the

4

CKSP

BA

value).

.

for

values

Use

seconds

,

to

4

+/

CE

A

.

4

G/n

make

5

0

key

5

function,

keys

The

(Giga/nano),

5

as

Hz)

,

continuous

4

.

toggle

(If you

.

+/

applicable

such

the

to

4



M/

adjustments

changes

5

0

already

have

the

of

right

(Mega/micro),

5

addition

In

.

,

sign of

the

pressed

while

or

angle

as

Getting

Acquainted with

the

HP

8530A

Receiver

1-17

Front Panel Overview

Table 1-1. Numeric Value Terminator Key Usage

Key

Name

G/n { GHz { { ns

M/



k/m milli degrees kHz { { ms

1

x1

1

4x15

Other Keys in the Entry Block

4

PRIOR MENU

4

=MARKER

4

=MARKER

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

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

could

ou

Y

Another

example

(for

display

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,

the

set

have

use

way to

assume

,

assume the

,

reference

4

=MARKER

you want

line

Angle Frequency Power Power Slope Time

{ MHz { {

degrees Hz dBm dB/Ghz s

always represents single units.

value

line

4

STOP

to another

the

to

4

V

REF

marker

ALUE

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



s

4

START54=MARKER

4

5

=MARKER

function.

the

of

value

4

5

=MARKER

.

5

active

5

,

As

and

5

.The

an

marker

the

4

ENTRY

function

function.

OFF

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

the

Getting Acquainted

1-18

with

HP

8530A

Receiver

MENUS Block

Front Panel Overview

The four keys under MENUS are

CAL Softkeys under

(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

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

the data

Saves

Displays

erforms trace

P

you

under

shows

markers

marker

search

list

MARKER

Allows

Softkeys

marker

measurement

Simple

4

Marker

4

5,4

CAL

DOMAIN

4

5

allow you to perform an antenna, radar cross section

CAL

4

DISPLAY

memory traces

change display

to

choose video

to

4

MARKER

amplitude

trace

mode

modes

5

trace to

math functions

5

Marker

.

the

on

.

5,4

DISPLAY

:

temporary storage

.

on memory

intensity or

settings for

activate

to

you

allow

phase

or

display

values

Functions

trace

are:

.

5

, and

an

for

4

MARKER

memory.

traces.

.

colors

external

up

desired

a

to

5

:

monitor

markers

ve

point

on

.

Each

.

the

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

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

touch. Pressing

4

LOCAL

peripherals and other instruments.

4

5

SAVE

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

saving

or

on,

state

A

stimulus

key has two uses:

4

5

LOCAL

5

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

and

4

to

it

you

if

dened

is

parameter

,

RECALL

register

press

5

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

4

USER

as

,

returns control to you.

receiver

The

8.

.

PRESET

the

format,

5

condition

and

response

of

will

all

return

current

settings

4

LOCAL

state

that

to

measurement

.

5,4

SAVE

whenever

settings

5,4

RECALL

the

including

,

5

, and

4

USER PRESET

instrument

all domain,

turned

is

5

.

the

Getting Acquainted

1-20

with

HP

8530A

Receiver

AUXILIARY MENUS Block

Front Panel Overview

The \AUXILIARY MENUS" contain the

4

5

COPY

4

DISC

or select an external disc drive.

4

SYSTEM

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.

controls hardcopy output, either printing or plotting.

5

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

5

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

4

COPY

5,4

DISC

5

, and

4

SYSTEM

5

keys.

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

For example, assume you choose the following measurement settings.

mode

Channel 1

Angle Domain

Parameter 3

Log mag (format)

Reference

Scale

automatically

channels

the

all

except

5

stimulus

Recall

or

state

works

or

(1

(Frequency

(1,

display

(any

in

10

0

dB/div

remembers most measurement settings. When you switch back and

domains

,

lower-level settings

settings.)

This

functions

memory

by

2)

3,

2,

and

above list

the

dB

,

or

.

."

assigning

,

Angle

4)

format)

reference

remembers

parameters

,

This feature

ability

hierarchy

a

Time)

or

line)

,

you used

remember

to

settings you

all

display

or

last. (This

is automatic

the

formats

make that

,

feature remembers

does

,and

settings

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

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

other

settings

advantage

1-22

along

Getting Acquainted

with all

that saved

is

the

instrument

the

with

HP

settings

8530A

,

states

Receiver

you

can

must

be

use

stored

the

to

SA

disc

.

VE/RECALL

.

resume. This

feature

.

Another

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

Softkeys

to

Select a frequency center point, a frequency

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.

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

span

4

four

MENU

STIMULUS

,

functional

, and the number

will

,it

5

keys

4

MENU

block.

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:

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.

osition

angle

use

4.

settings:

P

angle

(an

internal

It

.

the

90

the

will



with

selected

the

an

position

in

use

(b1/a1)

1

increment

Chapter

the

systems

On

Encoder automatically

time

each

taken).

explained

Example

example

The

Display:

Measured

Angle:

Start

Angle:

Stop

Increment

Frequency: 10 GHz (X-band)

that

positioner

the

Receivers

in

Measurement

arameter:

P

Angle:

that

\External

measurement

knows

reaches

use

Triggering"

Single

aram

P

0

+90



1

equipped

ARE

85370A

HP

increment

encoder

following

The receiver, using External

Encoder:

causes

where

triggering.

a

The

the

data

More

HP 85370A

receiver

point

this

on

to

is

Position

trigger

be

to

subject

is

Manual Measurement

2-4

Examples

Angle Scan Measurements

Setup

crosstalk

RF

the

errors,

power

desired

refer

by

value

to

pressing

using

setup

,

5

your

N

select

or

NNNNNNNNNNNNNNNNN

ANGLE

NN

N

1

Measurement

.

reduce

.

Change

.

setup

N

.

10

0

Then

dBm.

enter

NNNNNNNNNNNN

level

N

would

5

Antenna

.

4

DOMAIN

for

N

NN

N

SOURCE

N

Typical

Figure

Setup

est

Typical

Figure

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

Position Encoder.

Encoder.

Calibrate

you

If

Chapter 3.

Make

1.

Press

2.

Select angle measurements by pressing

3. Determine

STIMULUS

entry

T

typical

shows

2-1

want

Measurement Settings

4

RECALL

keys

a

Connections to Event Trigger could cause false triggers to the Position

calibrated

make

to

NNNNNNN

5

MORE

appropriate

an

4

MENU

for

,

N

5

POWER

example

2-1.

gain

RF

N

MENU

4

5

1

power

N

4

0

measurement

measurements

N

,

POWER

4

5

x1

antenna

NNNNNNNNNNNNNNNNNNNNNNNNN

NNNNNNN

FACTORY PRESET

N

NN

N

4

5

-

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

Choose Display Scale and Reference Line Settings

One step 40 dB or 60 dB patterns

ou

Y

Press

Individual

4

SCALE

rst

can

scale

5

4

MENU

5

the

set

can

RESPONSE

the

sets

5

you

,

time

to

values

suit

choose

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

5

LINEAR on POLAR

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

and

LINEAR on POLAR

display up

N

NN

N

MENU

scale

vertical

should

for

actual data.

the

NN

N

40

reference

and

graticule

estimate

display scale

for 40

N

NN

dB

in the

dB or

NN

N

PATTERN

controls

scale

(roughly)

After

.

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.

HP 8530A Keyword Dictionary

one

N

PATTERN

in

N

When

and

N

NN

minimum

N

.

making

is

60 dB

N

NN

or

dB/division.

in

the

patterns

NN

N

dB

60

maximum

measurement

step:

done

you

for details.

measurement

a

can

levels

readjust

power

.

for

Then

the

you

display

selects

4

Press

display

The

specify

Press

If you had pressed

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

4

SCALE

display

.

4

REF

REF POSN

5

the

to

has

Change

ALUE

V

5n4x15

4

5

4

bottom.

This

4

.

5

x1

reference line

a

of

value

the

4

10

0

5

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

.

5

x1

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

40 dB PATTERN

4 dB/division,

. This

reference

the

or

line

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

60 dB PATTERN

which

represents

to

line

provides

specic

a

dB as

0

10

, the reference line is now at the top of

40

power

follows:

level,

from

dB

the

which

top

of

you

the

can

Measurement Examples

Manual

2-7

Angle Scan Measurements

Measure the Antenna

To measure the antenna under test:

1. Press MEASUREMENT

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

Hint

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

receiver displays

example the

the

Move

3.

positioner

Results

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

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.

start angle

antenna

.

turns

example

an

for

MOVE

from

NNNNNNNNNNNNNNNNNNNNNNN

RESTART

POSITIONER

0

is

90

0

antenna

. This step ensures that the measurement starts at the



90

,so



+90

to

are

4

RESTART

ANGLE

move the



.

shown below:

The

5

forces the receiver to abandon the previous

FORWARD

positioner

receiver

you

will

have

about

to

measure

gone

enough.

far



93

0

.

antenna pattern

the

In

this

as the

Figure 2-2. Example Antenna Measurement

Manual Measurement

2-8

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.

you

Examples

want

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

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

Choose Display and Reference Settings

4

MENU

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

5

POWER MENU

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

,

POWER SOURCE 1

. Then enter the desired value.

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

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.

to

If you

Press

receiver

left-hand

Choosing

The

want

STIMULUS

underline

will

in

is

side

the

dierent

oint

Single

Ramp

Step Sweep

Frequency List

P

Sweep

measure

4

MENU

Hold

the

of

Best

sweep

mode

in the

mode

display

Sweep

modes

HP 8530A Keyword Dictionary

time:

a

N

NN

N

SINGLE

N

is not

Mode

at

N

NN

N

softkey

STIMULUS

.

making

receiver is

the

for

The

Y

when

measurements

our

one

N

5

MORE

the

,and

sweep

NN

N

HOLD

when

under

4

POLAR MAG

for details.

take

receiver

Measurements

4

MENU

will

measurement

the

Hold

in

are:

5

.

mode

The

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

5

and

LINEAR on POLAR

sweep

one

nished.

is

will

H

letter

.

4

POLAR MAG

stop

then

,

This

appear

, operate

5

and

The

.

means

on

the

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

repeats the measurement continuously

.

single measurement.

a

, and the letter

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

measurement

positioner

domain measurement

versus

positioner

a

using

receiver

concept,

in

moves

reections and

rotation

each

at

of

angle

system

measurement

hardware

and

antenna

an

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

measurement

starts

upon

procedures

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



Measurement

Typical

Figure

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

quasi-monostatic

a

conguration

for

used

Calibrate

Calibrate using the instructions provided in \RCS Calibration

for

monostatic

a

range

2-3.

and

.

RCS

bistatic

antenna

range

Setup

directional coupler

dual

A

.

" in Chapter 3.

Measurement Examples

Manual

is

2-13

Manual RCS Measurements

Choose Measurement Settings

1.

Select Frequency Domain measurements: Press

2.

Set the frequency sweep to Step mode: Press STIMULUS

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

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

STIMULUS

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.

keys:

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

MORE

CONTINUAL

4

MENU

and

,

3

measurement

the

NNNNNNNNNNNNNN

5

MORE

NNNNNNNNNNNNNNNNNNNNNNN

PARAM

.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TRIGGER MODE

NNNNNNNNNNNNNNNNNNNNNNNNNN

STIMULUS

not.

are

4

frequency

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TRIG SRC INTERNAL

key is underlined, but the

range and

4

DOMAIN

the number

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

5

FREQUENCY

4

5

MENU

NNNNNNNNNNNNNNNNNNNNNNN

PARAM 1

of points

.

NNNNNNNNNNNNNN

STEP

.

,

by pressing

NNNNNNNNNNNNNNNNNNNNNNN

PARAM 2

the

,

following

4

ART

ST

5

STOP

PARAM 1

the

12.4

5

target

4

STIMULUS

Note

Select the

6.

4

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

Set

8.

Choose Display F

Choose a data presentation format, scale

Scan Measurements".

5

G/n

4

5

G/n

4

MENU

When

frequency

high

measurement.

parameter you

place

in

N

5

NUMBER

using

measurement

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

at the

,

ormat

N

NN

N

OF

an

change

wish to

N

POINTS

8360

HP

is

accuracy

desired

N

NN

N

used

measure,

N

801

any

source,

family

positioner

, and reference value/position as explained in \Angle

RF

accurately

to

required,

is

press:

angle

the

phase

use

.

the

lock

second

the

sweep

rst

after

frequencies

RF

sweep

4

MENU

your

for

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

5

POWER MENU

4

8.2

5

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

or

You can make a single sweep measurement by pressing:

STIMULUS

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.

4

MENU

4

MENU

5

MORE

NNNNNNNNNNNNNN

MORE

NNNNNNNNNNNNNN

HOLD

NNNNNNNNNNNNNNNNNNNN

SINGLE

Figure 2-4.

If you want to measure

Press STIMULUS

receiver

receiver is in Hold mode

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

Choose

The

Single P

Ramp Sweep

will underline the

the

dierent

oint

4

Best

sweep

mode

one sweep at a time:

NNNNNNNNNNNN

NN

5

MENU

MORE

, and is not making measurements

Sweep

modes

Typical

NN

NNNNNNNNNNNNNN

HOLD

Mode

under

Measurement

. The letter

Manual

, then stop

H

will appear on the

Measurement Examples

. The

5

are:

Domain

Frequency

RCS

NNNNNNNNNNNNNNNNNN

SINGLE

. The receiver will take one sweep

softkey when the measurement is nished. This means the

Measurements

our

Y

for

STIMULUS

4

MENU

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

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

NNNNNNNNNNNNNNNNNNNN

SINGLE

NNNNNNNNNNNNNNNNNNNN

SINGLE

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

CONTINUAL

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

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

or

CONTINUAL

NNNNNNNNNNNNNNNNNNNNNNNNNN

5

MARKER 1

.

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

switches to Hold mode.

repeats the measurement continuously.

NNNNNNNNNNNNNN

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

MORE

MARKER to

MAXIMUM

4

MENU

NNNNNNNNNNNNNN

5

MORE

:

Time

The

the

Converting

o

T

4

DOMAIN

or

F

Manual

such as:

Choose the Display Format

ou

Y

4

LIN

Since you are now in the Time Domain, the

rather than frequency

adjust or measure in time:

Domain

convert

detailed

may

MAG

4

START

4

STOP

4

CENTER

4

5

SPAN

4

MARKER

Frequency

range

the

to

N

NN

N

5

TIME

information

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

Alias-Free Range,Range Resolution,Response Resolution

to

wish

4

,

5

LOG

5

Measurements

Domain

response

RCS

to

N

BAND

MAG

Time

N

set

5

Domain

Domain,

N

NN

N

PASS

on

display format.

the

FORMA

or

. This means that the following keys now

measurement

be

can

press:

Domain,

Time

4

T

MENU

seen.

The

N

5

REAL

N

converted

be

now

can

Operating

8530

HP

the

see

common

most

N

NN

.

X-axis of the data display is now showing time

formats

into

Programming

and

,and

Impulse Waveforms

Domain

Time

for

aect the Time Domain, and

Domain.

Time

are:

Thus

.

,

example

an

As

converted

been

Manual Measurement

2-16

of

into

Time

a

Examples

measurement,

RCS

an

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

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:

for a 150 foot range.

G/n

5

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

4

MARKER

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

5

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

Figure 2-6. Time Domain Measurement Showing Aliasing

Manual Measurement

2-18

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

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:

the response

START

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

SPECIFY GATE

N

NN

N

that

and

N

you

N

STOP

N

NN

N

wish

keys

to

or

keep

the

(normally

NN

N

CENTER

.

N

and

target

the

N

SPAN

NN

N

NN

keys

response).

to

center

the

Gating

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

Figure

responses outside

the

o

that

will

how

the

show

,

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

5

SPECIFY

MENU

NNNNNNNNNNNN

5

all OFF

NNNNNNN

5

DISPLAY MODE

side

by

in

work

also

receiver

both

use

Frequency

dierences

channels

various

the

of

.

more

and

GATE

N

NN

N

NN

N

5

FREQUENCY

NNNNNNNNNNN

NNNNNNNNNNNNNNNNNNNNNNNNN

.

NNNNNN

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

GRATICULE OVERLAY

Frequency

the

channels

Time

and

between

receiver

the

of

display

NNNNNNNNNNNNNNNNNNNNNNNNNN

N

NN

N

NNNNNNN

OFF

GATE

NNNNNNNNNNNNNNNNNNNNNNNNN

DUAL CHANNEL

Notice

Gating

shows

Viewing

T

measurement

adjustment

parameter

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

To display both measurement channels

4

DISPLAY

You can also press

side

2-8.

gate

the

of

Domain

show

to

Domain

signal

gated

a

The

.

parameters

, press:

NNNNNN

or

have

reduce

to

the

Gating

and

measurement

two

such

,

NNNNNNNNNNNNNNNNN

SPLIT

been

dierences

un-gated

an

scale

as;

, to view the two traces superimposed, or

Turned

Gate

The

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

the active

is

you

1

make

will

Examples

Currently

changes

any

4

CHANNEL

2-20

2

Manual Measurement

channel

.

5

aect

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

5,4

SCALE

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:

4

CHANNEL 154DOMAIN

4

CHANNEL 254DOMAIN

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

ou

Y

shows

can

an

REF VALUE

now

example

5,4

5

NNNNNNNNNNNNNNNNNNNNNNN

GATE ON

compare

of

5

REF POSN

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TIME BANDPASS

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

N

TIME BANDPASS

the

this

,and

dierence

.

4

FORMAT

between

5

keys. If you press the

and ungated

gated

the

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

N

GRATICULE OVERLAY

responses.

4

PARAM

Figure 2-9

5

,

key

Figure 2-9. Dual

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

press:

N

4

CHANNEL

4

CHANNEL

4

5

2

DOMAIN

N

NN

N

5

FREQUENCY

1

N

5

FREQUENCY

N

Display with Time Domain

N

NN

N

Manual

Measurement Examples

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

Figure

into

go

to

have

don't

ou

Y

the

a

N

prior

you

N

Set

wish

N

NN

N

knowledge

N

NN

Frequency

Domain,

Then,

4

DOMAIN

without ever going into the Time Domain.

Domain.

by

or

whenever

N

NN

5

SPECIFY GATE

2-10.

Domain to

Time

gate

turn

to

N

NN

GATE ON

at

N

of

N

on

NN

the

where

the

proper

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

frequencies

system.

calibration

(dB

antenna

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

Calibration

RCS

Network Analyzer

Response

a

using

Response

calibration

the

empty

clutter

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.

antenna

.

Background

and

calibration

portion

After

analyzer calibration

target

the

of

target.

chamber

performing

dBsm (decibels

The

during network

calibration

known

of

calibration

Background

characterize

to

RCS

an

square

per

greatly

transfers the

errors

reduces

radar

measures

portion

calibration,

meter).

reduces

analysis measurements

range

section.

cross

the

measures

compensate

and

measurements

repeatable

accuracy

reections

The

of

the

for

are

.

of

Calibration

3-2

Antenna and

RCS

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

.

points

smaller

Y

3.

or

some

again.)

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

select

(in

receivers

8530

Angle

in

The

, adapters

Domain.

Consideration

consideration.

important

situations

, and so forth, connected in one specic

can

ou

(Y

require

to

thing

where

a calibration applies to a specic

redene

invalid

any

(Some

angle

will

calibration

HP

while

special

results.

avoid

and

valid.

be

swept

perform

can

ou

Y

4.

Single

ON again.)

5. Y

Setting

Other

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

parameter

must

The

To understand the considerations involved, remember that

hardware

way).

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

b1/a1.)

frequency

change

can

ou

Changes that

settings can

and

when

know

instrument will

setup (a specic collection of cables

As long

b1/a1

as

a

measurement.

start

be changed,

valid

get

results

the

not

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

the calibration

and

frequency

stop

and

Require Special

but require

measurement

are valid,

you.

warn

sweep

Step

or

Ramp

mode),

to

you

remember

data

parameter

turn

then

the

that

is

would

key

calibration

you

result.

be

to

a

Antenna

and RCS

Calibration

3-3

Calibration Fundamentals

Changing Stimulus Values

Changing any of the following settings will cause the message

INVALID

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

Selecting

you

If

greater

automatically

to be displayed. Calibration remains ON.

oints

P

Greater

a

calibrate

number

using

points

of

turned

Number

certain

a

If

.

and

O,

of

number

attempt

you

CORRECTION

of

points

to

,

select

RESET

cannot

you

greater

a

displayed.

is

CAUTION: CORRECTION MAY BE

CORRECTION RESET

perform

number

a

of

is displayed.

measurement

calibration

,

points

using

a

is

veraging

Using

or

F

device

Hewlett-P

of

accomplished

factor

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

averages).

A

calibrations

all

measurement.

ackard

calibration

the

the active

as

by

List,

the

use

,

general,

In

recommends

calibration

RCS

(in

turning

each

A

function during

data

or

same

that

veraging

is

point

averaging

an

increase

is

before

averaging

the

n

greater

use

you

this

ON

the calibration.

averaged

factor

averaging

the

background

beginning

times (where

the

than

16

or

8

of

factor

calibration).

calibration,

the

is

n

will

for

selected

be

most

for

used

measurements

isolation

the

can

This

leaving

then

number

the

portion

easily

be

averaging

of

.

Calibration

3-4

Antenna and

RCS

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

Calibration

3-6

Antenna and

RCS

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

over

the

sets

a

gain

antenna

These

."

nal

can

range

be

of

.

standard

calibration,

which,

results

units

.

Domain,

the

compared

is

internal

an

in

when

antenna calibration,

In

.

antenna gain

of

Domain.

which

nished

Set

Cal

Angle

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

HP recommends

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:

Domain

Frequency

A

antenna

denitions

dierences

measurement,

measurement

stored

and

that

calibration

measured

is

Any

.

are

internal

in

Frequency

Domain

calibrate

you

the

result

data

Calibration

data

its

and

dierences

coecients

error

calibrated

in

expressed

is

registers

Domain

Frequency

using

performance

stored

are

in

disc

to

or

Calibrations

Angle

in

During

.

le

the

one

to

set

\cal

subtracted

(dBi). Cal

calibrates

or

register

from

Antenna

and RCS

Calibration

3-7

Antenna Calibration

Calibration

3-8

Antenna and

RCS

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

highlighted.

3.

Press

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

AC_NAR1

Are

ou

Y

If

Create

Denition

save

can

Note

Antenna/RCS Cal Disc

NNNNNNNNNNNNNN

4

5

DISC

AC_NAR1

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

LOAD FILE

.

Not

own

your

the

at

",

in

text

NNNNNNNNNNNNNNNNNNNNNNNNNN

LOAD

Using

CAL KITS

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

.

One of

denition

cal

end

ASCII

plain

you

If

more standard

what happens

frequencies?" The

the calibration

the Pre-Dened

chapter

this

of

format.

calibrate

into the HP 8530A's disc drive.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

ANTENNA CAL DEF

Narda Horns:

explained

as

le

will

ou

Y

.

frequency

wide

a

over

of

the

.

the

is:

standard

antennas

gain

when

answer

data for

two

, the receiver will display a le directory

Antenna

may

that

Gain

and a

need

\When

us:

have

overlap

was

use

to

overlapping

the

,

measured

\Creating

in

need

Some

standard

Where

personal

a

range

users

gain

frequencies

the

gain

Standard

a

computer

you

,

asked

have

antennas

antenna

text editor

or

two

calibrating,

receiver

last.

that

uses

Performing an Antenna Calibration

Frequency Domain Calibration

Finding Boresight

,

Initial

Setup

Mount

1.

system.

2.

Press:

3.

Press:

4.

Press: STIMULUS

5. Press

frequency

Press

6.

Select

7.

the

4

RECALL

4

DOMAIN

4

CENTER

4

MARKER

the

standard

5

range

5

desired axis

gain

NNNNNNNNNNNNNN

5

and enter a frequency in the approximate center of the calibration

.

NNNNNNNNNNNNNNNNNNNNNNNNN

MORE

FACTORY PRESET

NNNNNNNNNNNNNNNNNNNN

NNNNNNNNN

FREQUENCY

4

MENU

.

antenna

NNNNNNNNNNNNNNNNNNN

.

NNNNNNNNNNNNNNNNNNN

5

SINGLE POINT

positioner

the

on

the

on

NNNNNNNNNNNNNNNNNNN

proper

.

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

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

will work

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

the

sweep

the

inconvenient

size

Note

Sometimes

to

during

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

vii.

SIZE

STEP

Frequency

modes

increment

is

that

cover the

the procedure

i.

Press STIMULUS

ii.

Press

GHZ).

8.2

iii.

Press

iv.

Press

a moment that your standard gain antenna has documented

MHz. Y

interpolate between known

v.

Press

measurement, based on the selected step size.

vi.

Press

. Press

but the Frequency List mode is strongly recommended

function

List

only

frequency

increment

convenient

Ramp

congured.

source

receiver

NNNNNNNNNNNNNN

N

NNNNNNNNNNNNNN

N

Sweep

.

wide frequency

whole frequency

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

EDIT

N

NN

N

STOP

and

NNNNNNNNNNNNNNNNNNNNNN

NNNNNN

STEP SIZE

ou can choose smaller increments (for example

DONE

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

N

NN

N

again.

DONE

N

NN

N

FREQUENCY

4

CENTER

,below.

allows

mode

allow

values

.

mode

Ramp

addition,

In

the

and

below.

4

MENU

SEGMENT: START

enter

and enter the desired frequency increment value

N

NN

N

LIST

is

you

.

N

5

followed by the desired frequency, proceed to

NN

increment frequency

calibration.

a

N

NN

N

NN

in

not

to

the

.

POINTS

of

calibration

the

SIZE

STEP

depending

,

function

two

use

,

case

(for

mode.

List

BNC

or

enter

,25

a

enter

to

you

better

This

RF

ranges

5

the

N

when

choose

to

limits

17.67

(like

always

is not

Sweep

NNNNNNNNNNNNNN

MORE

to

mode

Ramp

source

require

.

range

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN

EDIT LIST

and enter the desired start frequency (for example,

desired

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

select

known

performing

NN

N

a

NUMBER

exibility

MHz).

usable

will

Sweep

.

If

requires

you

is

this

frequency

stop

Frequency

N

,

allows

on

systems

is

more

the

example

4

5

MENU

. The Frequency List

. This

and

Ramp

receiver

the

and

results

often

and

choose

to

you

system

your

how

use

that

connections

standard

entire

12.4

,

gain values every 50

MHz), and the receiver will

between

gain

frequency

GHz).

. Assume for

Antenna

why

is

step

chooses

in

a

an LO

antennas

step

is

the

range

Calibration

3-10

Antenna and

RCS

Antenna Calibration Steps

Antenna Calibration

2. Press the

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

ANT. CAL uWave A.1

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."

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

to \Finishing the Gain Calibration," below.

Note

4

5

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

CAL

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

FAR FIELD:RESPONSE

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

DONE RESPONSE

If you see the error message:

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

frequencies.

Use

b.

antenna

standard

range

antenna

section

Select

c.

standard

an

standard

a

is

that

of

may

on

calibration

a

specied

antenna

gain

antenna.

not

creating

antenna

gain

gain antenna

have

standard

frequency

CAUTION: ADDITIONAL STANDARDS NEEDED

standard

cover the

to

denition

The

entered

and

antenna

gain

that covers

selected frequency

really has

values

gain

span

the

who created

antenna

that

calibration

person

do

the

for its

denitions

within

is

cover

to

entire

entries for

the

entire

over

the

frequency

range:

the

\denition"

range

this

in

,

frequency

the

again.

and proceed

additional

range

Make

entire

Refer

.

chapter

,

your

If

.

the

sure

frequency

for

le

the

to

.

of

range

that

the

than one

calibrating

are

you

If

4.

antenna:

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:

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

have

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

Finishing the Gain Calibration

ou are

Y

5.

want

between

the

found.

appropriate

the

NNNNNNNNNNNNNNNNNN

DONE RESPONSE

selected. There are either gaps between adjacent denitions

done

now

perform an

to

inputs

for

standard

sub-steps

NNNNNNNNNNNNNNNNNNNNNNN

with

\isolation

(either

reference-to-test or

antenna.

gain

standard

for

when you are done

CAUTION: ADDITIONAL STANDARDS

gain

the

gain

standard

each

portion

calibration."

frequency

wide

a

range

antenna

gain

.

the

of

An

test-to-test),

denition

antenna

calibration.

isolation

requiring

,

more

the

from

need

you

NEEDED

you

Now

calibration

requires

and

softkey

to

, or they do not provide

should

reduces

standard gain

menu.

measure

appears, then the

high-quality

a

.

decide

crosstalk

if

50

you

load.

Antenna

and RCS

Calibration

3-11

Antenna Calibration

a.

If you

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.

do not

want to perform an Isolation Calibration, press

Table 3-1. Proper Connector Torque

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

OMIT ISOLATION

and

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

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

FIELD

and

now

receiver

The

.

Cal

a

N

NN

N

.

the

turn calibration

Set

A

cal set

egister

R

menu

will

of

will

Torque

N-cm

perform

cal

eight

saved

be

ON,

so

Torque

in-lbs

isolation

the

registers

set

that

to

measurement

any

Part Number

calibration.

will

register

Wrench

appear

.

you

Press

.

make

will

any

be

eight

the

of

calibrated.

Calibration

3-12

Antenna and

RCS

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

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

in

gain

able

T

standard

shown

portion

gain

antenna

to prevent

3-2

with

calibration.

the

of

Set Register."

load.



50

a

leakage

RF

Make

.

Now you

sure

should

NNNNNNNNNNNNNNNNNNNNNNNNN

NNNNN

OMIT ISOLATION

load's

the

Antenna

decide

NNNNNNNNNNNNNN

connector

and RCS

you

if

and

is

Calibration

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

Calibration

3-14

Antenna and

RCS

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

useful

1.

Now

now

is so

easy

it

can

you

Domain,

go

CORRECTION

the

in

calibration,

Frequency

why

convenient

precisely

calibration

a

set

cal

display

N

NN

SET

CAL

even

valid,

original

the

N

to

N

the

N

Cal

N

1

step

which

Set

message

NN

to

though

Frequency

known,

a

you

,

to

will

N

NN

N

is

reason

know

Try

created

the

now

N

ON

still

in

another

is

This

Entering

Thus

set.

Things

Assume

and

receivers

N

NN

CORRECTION

calibration

the

valid.

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

you

save

you

N

frequencies

List mode

size

frequencies

the

in

Register

turn the

you

makes

Frequency

CAUTION:

calibration ON

are

Domain

calibrations

in the

are

calibration.

mode

List

Some HP

press

Domain

8530A

4

CAL

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

measurement

RCS

position,

measurements

target.

the

Usually

receiver

be

Remember

are

ou

Y

using

If

gating

,

measuring

a

has

frequency

limitations

limited

a

where

list

not

Do

.

frequency

points

the

use

span

gating

or

are

if:

number

evenly spaced.

not

of points

.

Calibration

3-16

Antenna and

RCS

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

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

step

calibration.

the

Resolution

Range

Free

Requirements

Frequency Domain

method

This

.

value

method

This

Angle

Domain.

Why?

, window

using one of the following methods:

,

exact

the

know

to

allows

is

you

preferable

Because

you

if

can

you

are

then

going

make

and gate settings you should use

,

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

veraging

A

Select

desired,

If

7.

RESPONSE

factor.

Perform the Calibration

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

9.

Press

gating

If

10.

settings

Antenna and

3-20

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

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

Desired)

(if

it

set

and

ON

NNNNNNNNNNNNNNNNNNNNNNNNN

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

TARGET RESPONSE

select

the

whether

N

press

calibration.

N

NN

GATING

4

CAL

aect

will

turn

4

MENU

NNNNNNNNNNNNNNNNNNNNNNN

5

RCS CAL

ON,

is

not

RCS

veraging

A

NNNNNNNNNNNNNNNNNNNNNNNNN

5

AVERAGING ON/restart

can

you

calibration,

the

aect

Calibration

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

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.

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

calibration data.

To perform the background calibration:

13. Remove the RCS target.

14.

15.

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

Press

TARGT RESP DONE

N

Press

MEASURE

NN

N

Press

calibration data.

DONE

RESP&BACK

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

DONE RESP&BACK

N

BACKGROUND

N

NN

N

NN

.

Now

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

select

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

MEASURE target name

cal

eight

of

the

one

set

. (This softkey displays

hold

registers

to

the

proceed

Now

16.

used

you

If

remember

is

this

often

Updating

Once calibration

update the

1. Make

2.

Press:

3.

Press

data:

You

a.

If

b.

set register

the

background. T

sure the

4

5

CAL

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

DONE RESP&BACK

store

can

change

you

measurements.

normal

with

single

to

N

NNNNNNNNNNNNNNNNNNNNNN

RCS CAL

sweep

change

Continual

the

Background

,

done

is

appropriate

updated

the

mounts

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

RCS

procedure),

this

the target

nd

to

mode

the

to

back

sweep

if

NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

UPDATE BACKGROUND

mode

.

mode

RCS

change

you

this:

do

o

RCS

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

calibration

regularly

the

calibration

can

you

,

to

is

the

response

type needed

mount,

ON.

register

store the

or

(earlier

background

the

which

updated

for

in

actual

holds

calibration

measurements

the original

changes

to

,

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

Calibration

3-22

Antenna and

RCS

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

MS

an

to

le

the

save

can

then

le

be

loaded

can

into

contain

the

up

receiver

to

plain

in

LIF

HP

or

the

from

\antenna

ASCII

format

disc).

The

.

disc

denitions

The

(which

le

denition

cal

."

DOS

seven



R

antenna

gain

above

However

which

,

following

by

are

Hewlett-P

a

,

.

pre-dened

a

,

shipped

was

the

provided

ackard

cal

mentioned

As

Disc

create

AC_NAR1

on

standard

denitions

.

,

in

Antenna

The

denition

receiver

\Loading

this

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.

Any

Interchange

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

Denition

Supplied

8530A

HP

AC_NAR1

(

ou

Y

.

the

section.

computer

Denition

Cal

not

shipped

is

is supplied

)

that

AC_NAR1

can save

(LIF).

can load

Cal Denition

ormat

F

The

\antenna

contains

with

on the

or

,

into the

ASCII

denition."

up

denition

cal

a

Antenna

denition

cal

a

HP 8530A

les

seven antenna

to

in

RCS/Cal

". Details

formatted

discs

to

memory

you

specic

a

for

data

gain

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

Dierence

Number

start

The

Choosing

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

For example:

Start frequency

Stop frequency =

the exact

that

even

frequency

between

frequency

of

stop

and

the

frequencies you

choose frequencies

you

only

you

if

your

of

your

of

frequency

frequencies

Number

Frequency

the

frequency

01).

= 2 GHz

4GHz

make

standard.

.

points

of

increment,

you

want

that

measurements

points

oints

P

(the

already

Increment

know

divide

cover

single

at

frequency

from

frequency

the

entire

the

frequencies

increment).

the

antenna

the

in

use

to

denition.

range

published

by

span

of

.

data.

the

Hewlett-P

your

standard

ackard

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

2x109/(2101) = 100 MHz

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

From there,20

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.

additional

number of points01

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

:

Typical

Choose

1.

respectively

the

Figure

start

.

and

3-4.

stop

Standard

frequencies

Gain

Examples

.

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

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:

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

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

your

standard antenna, determine the gain at each frequency increment.

Table 3-3. Example Standard Gain Antenna Performance Table

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

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

values into

gain

these

simply

points,

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

gain values

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

values

When

calibration

do

3-26

enter

\Even

must

you

have

not

Antenna and

Frequency

. Notice that these lines do

represent

perform

be

can

the same

be

to

RCS

Increments"

evenly

actual

the

performed

Calibration

spaced

calibration

any

at

frequencies

the

as

ASCII

the

explains

NOT

frequency

you

frequencies

MUST

ou

Y

.

le

data

.

why

between

specify the frequency of

.

values

can

in

choose

you

the

any

choose

antenna

use

frequency

frequencies

The

.

denition.

evenly-spaced

If you look at

BEGIN

and

END

each gain value

points

you

used

(When

frequency

hold the

. Because

wish.

the

in

calibrating,

A

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

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

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

with

two

Denitions", later in this chapter.

must contain

, the receiver

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

all

the frequencies required by your measurements. When

does not

interpolate between

Antenna RCS/Cal Disc

AC_NAR1

.

calibration points

, which was supplied

.

making

Typical

Figure

3-5.

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

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

a Cal

dening the

Denition

line starts

This

number

\Creating

\1" should

not

incremented

be

with

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

the

this

,

.

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

softkey

be

FREQ

number

the

rmware

the

any

to

changed

21

MAG

of

revisions

dene the start frequency

denes

This

\SASGH-1.10"

label

the

VAR

Enter

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

SEG LIST BEGIN

SEG 2000000000 4000000000 21

SEG LIST END

These three lines

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

BEGIN

1.70E1

1.714E1

1.725E1

.

SASGH-1.10

label

you

label

reect

to

frequency

may

this

for

want,

type

the

points

require this

antenna

up

and

at

denition.

maximum of

a

to

frequency

end

the

line

, stop frequency

label

change

can

You

characters

ten

the

of

range

(where

line

this

of

.)

, and the number of points (again).

the

It

.

standard

number

the

recommended

is

antenna.

gain

located

21 is

Calibration

3-28

Antenna and

RCS

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

Loading the Cal Denition into the HP 8530A

cal

a

load

o

T

Insert

1.

Press

2.

all

Use

3.

Press

the softkeys

the

4

DISC

denition les

cal

the knob

4

CAL

N

ANT.

The lename must begin with the three characters:

(The two lettersACfollowed by an underscore character.)

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

denition

disc

5

Notice

.

5

N

NN

CAL

buttons

N

LOAD

to

N

receiver

N

LOAD

you

antenna

N

AC_

will

N

FILE

chose

denition

display

N

NN

N

.

for

le

a

that cal

names