Hp 86908 User manual

HEWLETT.

PACKARD

Multi-band

capability

provides

un-

precedented

versatility

Interchangeable

RF

Units

give

you

multi-band

capability

at

low

cost

Dials

are

easy

to

change,

keyed

1OM

1169/7.5M0370

Printed

In

U.S.A.

CONVERTIBLE

SWEEP

OSCILLATORS

model

86908

8691-8697

8706A,

8707A

86988,86998

TECHNICAL DATA 1 MAR

70

Page 2

Introduction

The Hewlett-Packard 8690B Sweep Oscillator forms the

basis of many types

of

swept-frequency systems. The 8690B

Sweep Oscillator accepts nine RF units capable

of

cover-

ing the frequency range from 0.4 MHz to 40 GHz. An

8690B/RF Unit may be used alone or with a wide variety

of

accessory equipment. For example, multi-band sequen-

tially swept coverage

is

provided

by

employing the

HP

8706A Control Unit and up to three 8707A RF Unit Hold-

ers, permitting the 8690B Mainframe to drive

as

many

as

eight RF unit sweep oscillators.

86908

Sweep

Oscillator

The Hewlett-Packard 8690B Sweep Oscillator combines

interchangeable RF units with high accuracy, versatility, and

ease

of

operation to bring you all the advantages

of

single

unit sweep oscillators plus economical multi-band capability.

With

no adjustments required, the changing

of

RF units

is quick and

easy

and the snap-in dial

is

keyed for accurate

positioning. The front panel has a logical, straightforward

layout for ease

of

operation. The frequency dial

is

the full

width

of

the instrument for maximum resolution.

Careful design

of

all-new solid-state power supplies re-

sults in exceptionally low residual FM, and provides rugged

protection against system transients.

INC.

FM

=

750kHz

j_

250

kHz

T

Fi9ure

1.

Low incidental FM

of

square-wave modulated

8693B is shown in this oscillogram. Measurement made

with

HP

2590B Microwave Frequency Converter.

RF

Units

The

HP

8698B (400 kHz -110

MHz)

and 8699B (1

oo

MHz - 4

GHz)

Solid-State RF Units provide four decades

of frequency coverage with only two plug-ins.

By

use

of

heterodyne techniques, careful filtering, and advanced mi-

crocircuit technology, broadband coverage

is

achieved along

with superior performance.

Microwave RF units employ high reliability Backward

Wave Oscillator tubes

(BWO)

which carry an uncondi-

tional one-year warranty.

Two types

of

microwave RF units are available, permit-

ting selection

to

meet any application requirement.

HP

diode modulation and leveling are available in the

Model8690B

"B" type RF units from 1 to 12.4 GHz. The 8691-4B RF

Units offer exceptional frequency accuracy (between 0.5%

and

1%)

over a wide range of modulation conditions.

HP

diode RF units are the only RF units that specify full

power frequency accuracy over a 10-dB dynamic range,

considerably enhancing measurement accuracy. All modula-

tion functions including leveling are performed independent

of

the backward-wave oscillator tube

(BWO).

The result

is

the virtual elimination

of

frequency pulling during either

modulation or leveling, which, in turn, results in extremely

high frequency accuracy and linearity and very low inci-

dental FM. Figure 1 illustrates the low incidental FM

associated with square-wave AM.

The

"A"

series

of

RF units employs conventional

BWO

grid modulation for AM functions. This series covers the

entire 1-40

GHz

spectrum in seven models (8691A-8697A)

and

is

used in the bands above 12.4 GHz, where

attenu-

ators are not available, and in lower bands when modulation

requirements are

less

demanding.

Sweep

Functions

and

Markers

The 8690B Sweep Oscillators provide a broadband "start-

stop" sweep whose end points can be set anywhere in the

band. Independent controls set the start and stop frequencies

on the slide-rule scale. Thus the units can sweep up or down,

depending only on the setting of the start frequency with

respect to the stop frequency. There

is

no interaction

be-

tween the start and stop control settings. Selecting the start-

stop sweep

is

simply a matter

of

pushing a button.

Two independent frequency markers, set separately on

the dial and direct-reading in GHz, can be positioned

any-

where in the band. The markers amplitude-modulate the

RF output, providing triangular markers. These markers

have points sharp enough to give high resolution on narrow

sweeps, yet are broad enough

to

be quite visible on even the

broadest sweeps. Figure 2A shows that the markers are

plainly visible on a full-band sweep. In addition, marker

amplitude can be adjusted from the front panel. Adding

the markers to the display

is

again a matter

of

pushing

buttons.

The markers can also be used

as

end points for a second

broadband sweep which starts at the Marker 1 frequency

and ends at the Marker 2 frequency. Thus, the 8690B

Sweep Oscillators have two independently adjustable broad-

band sweeps, providing a high degree

of

flexibility. For

example, should the start-stop sweep reveal a particular area

of

interest, the markers can be adjusted to bracket the area;

then a simple depression of the Marker Sweep button

ex-

pands the bracketed area to cover the full horizontal scale

of

the indicating device-oscilloscope or X-Y recorder.

Figure

2B

illustrates this display expansion. The marker

sweep need not

be

within the start-stop sweep. Thus the

start-stop sweep can be set to cover one range, such

as

the

passband

of

a filter, and the marker sweep can be set to

cover another range, such

as

the stop band.

Besides sweeping from a start frequency to a stop fre-

quency, the 8690's provide a calibrated narrow-band sweep

which

is

symmetrical about a center frequency. Simply

press the

.!lF

button, set the center frequency with the Start-

CW

control, and adjust the deviation with the

Stop-LlF

control. Total swing

is

indicated on the bottom slide-rule

)

Model8690B

A

B

Figure

2.

(A)

Full-band start-stop sweep with markers.

(B)

Expansion

of

2A display between markers on Marker Sweep.

scale. The frequency markers can be applied

to

the llF

sweep

as

well

as

the start-stop sweep.

As noted above, the Start-CW and Stop-llF controls are

used for the

llF

sweep. Thus the marker controls can be

used for wideband sweep applications and the start-stop

controls for

llF

operation. This provides independently

adjustable wide and narrow band sweep modes with full

cali-

bration for both modes.

Sweep

Modes

Recurrent, triggered, and manual sweeps are available.

Recurrent and triggered sweep times are adjustable from

0.01 to 100 seconds, and the triggered sweeps can be

syn-

chronized from an external source or manually (front-

panel pushbutton) for photography or

X-Y

recording. To

enhance the clarity of oscilloscope presentations, RF power

is

blanked during retrace to produce a zero baseline; how-

ever, RF is restored before the start of the subsequent sweep

to eliminate transients during the early part

of

the sweep.

Blanking can be disabled, when desired, with a rear-panel

switch. Oscilloscope photography

of

slow sweeps

is

simpli-

fied

by

a front-panel sweep indicator. This indicator turns

on automatically at the start

of

the sweep and turns off at

the end. Thus there

is

no guesswork about when to close

the shutter and remove the film and no time wasted waiting

to be sure the sweep

is

finished.

For X-Y recorder presentation, an automatic pen-lift

circuit

is

provided. The circuit drops the pen during the

stabilizing period prior to the sweep and lifts the pen dur-

ing the second stabilizing period which occurs at the end of

Page 3

the sweep just before retrace. Thus transients and retrace

lines are eliminated from X-Y plots.

On

manual sweep, a front-panel control varies the RF

frequency between the limits set on the selected sweep func-

tion.

With

the

use

of the manual sweep,

X-Y

recorder setup

time

is

reduced to seconds.

The sweepers provide their own voltage ramp concur-

rently with the RF sweep for driving the horizontal systems

of

oscilloscopes and X-Y recorders. While this ramp varies

somewhat from unit to unit, it remains the same within a

given unit regardless

of

sweep mode, duration, or direction.

Once the sweep end points have been set on the recording

device, they will remain the same for any sweep. Thus the

broad flexibility and simple push-button operation

of

these

units can be fully utilized.

In

addition to the sweep voltage from the sweep oscil-

lator, the RF units provide a reference voltage which

is

proportional to the output frequency. This reference

is

about zero at the lowest frequency and increases about 40

volts per octave. The reference, available at the rear

of

the

RF units, can be used

to

drive an external monitor when a

continuous indication of frequency

is

required.

It

is

also

especially useful with the new

HP

8410A Network Analyzer

system to enable accurate phase-lock synchronization at high

sweep speeds.

Leveling

The 8690B Sweep Oscillators are designed for external,

closed-loop leveling. This technique minimizes the varia-

tions in output amplitude with frequency which are inherent

in backward-wave oscillators. A basic leveling setup

is

shown in Figure

3.

The leveling signal, the result

of

RF

sampling

by

the directional coupler and detection

by

a

crystal detector,

is

applied to a leveling amplifier built into

the sweep oscillator. The amplified signal

is

applied to the

diode attenuator in the "B" series

of

RF units and to

the

BWO

grid in the·

"A"

series to maintain a constant

power at the output

of

the directional coupler. External

leveling therefore eliminates the frequency-dependent trans-

mission characteristics

of

any components (cables, connec-

tors, amplifiers, filters, etc.) between the oscillator and

sampling point.

External leveling with directional couplers has the further

advantage of virtually eliminating source mismatch. Thus

leveled power can be established at

any

point in a system,

even though it

is

remote from the source. The degree of

leveling

is

determined primarily

by

the characteristics

of

the

directional coupler and detector.

86908

w

DETECTOR

Figure 3. Basic leveling configuration in coax.

Page 4

86908

OSCILLOSCOPE

SWEEP

·~c

~

®HO~IZ

V~T

(,)

l I

SWEEP

J I

L DETECTORS

r-v

'-1i

--~

1.::::

=TEST

DEVICE

DUAL

' 0

DIRECTIONAL '

SHORT

COUPLER

Figure 4. Coaxial reflectometer.

Internal leveling

is

available

as

Option

001

on most RF

units operating below 12.4 GHz. The directional coupler

and detector

of

Figure 3 are located within the RF unit and

the output

of

the coupler becomes the output

of

the sweep

oscillator. Internally leveled units are useful in less critical

applications

in

which transmission variations between

os-

cillator and test point are not significant or a package free

of

external elements

is

desired.

Modulation

All modulation functions are selected

by

pushbutton and

can be used simultaneously. Included

is

internal square-

wave modulation, with a range

of

950 to 1050 Hz, plus

external

AM

and FM. The external

AM

input

is

de-coupled

to permit de control

of

amplitude and can be utilized even

during leveled operation.

The

external

FM

input

is

also

de-

coupled to permit external frequency programming, and

the response to a full-band step change

is

typically less than

2 milliseconds. The frequency response to sinusoidal

FM

is

150 Hz for full-band swing. Maximum swing decreases

to about

1%

of

the band at

20

kHz. Greater-than-specified

deviations at modulating signals above 150

Hz

can be ob-

tained at a sacrifice

in

linearity.

Swept

Systems

Applications

The

range

of

application for swept-frequency techniques

covers all microwave measurement areas: impedance, attenu-

-hp-

1416A

-hp-

141

A Swept Frequency

Oscilloscope Indicator

0

-hp-86908

Sweep

Oscillator

Device

under test

~~~t~~~~~.~

-hp-

817A

-hp-

907A

Sliding Load

Figure 5.

The

817A Swept Slotted Line system provides

inexpensive and precise SWR measurement from 1.8 to 18

GHz.

Model8690B

ation, power, frequency, etc. The most widely used swept-

frequency system has been the reflectometer, which,

in

measuring return loss and SWR, provides impedance infor-

mation. Figure 4 illustrates the basic reflectometer setup in

coax; the waveguide setup

is

similar. Above 4 GHz, the low

directivity

of

coaxial directional couplers has been a serious

limitation

in

the coaxial reflectometer. Hewlett-Packard,

therefore, recently developed the Model 817A Swept Slot-

ted Line system capable

of

measuring very low standing-

wave ratios with a high degree

of

accuracy from 1.8 to 18

GHz. The design simplicity

of

the 817A Swept Slotted

Line system shown

in

Figure 5 provides broadband, pre-

cision, coaxial SWR measurements at roughly a third

of

the

cost

of

previously available hardware.

Frequency response, whether

in

the form

of

attenuation

in a passive device or gain

in

an

active device,

is

another

parameter readily measured on a swept-frequency basis. A

typical measurement setup in waveguide

is

shown in Fig-

ure

6.

The new Hewlett-Packard Model 8410A Network Ana-

lyzer provides one simple system capable

of

measuring both

amplitude and phase

of

all network parameters from 110

MHz

to 12.4 GHz.

The

8410A Network Analyzer

is

shown

in Figure

7,

with the

HP

8690B Sweep Oscillator measuring

both the amplitude and phase transmission characteristics

of

a

YIG

filter. The 8410A

is

capable

of

measuring phase,

gain, loss, impedance, admittance, reflection coefficient, and

angle. Phase and amplitude output data may be obtained

either from a linear meter readout or in polar form with the

HP

8414A Polar Display.

The

HP

sweeper has been designed to

be

especially com-

patible with the advanced 8410A Network Analyzer system.

The 8690B supplies a sweep reference voltage output

which

is

used to synchronize the 8410A sampling phase-

lock oscillator permitting phase-lock operation at the fastest

sweep speeds, providing a flicker-free oscilloscope readout.

The 8690B Oscillator has been designed to provide a de-

layed sweep start-up, enabling the 8410A Network Analyzer

system to phase-lock before the initiation

of

the sweep. This

delayed sweep start-up capability

is

also especially useful

86908

OSCILLOSCOPE

»m

"'

[;J

I

\:ili:L,

~"'

t---~1

SWEEP r

t-l

:J]_DETECTOR

i

·~~1::'·-x}""u~,"

i COUPLER

I

I TEST

I !. T DEVICE

I

r-x--

~

'-1

10/20D8

1------p.--.--~

DIRECTIONAL

DETECTOR

COUPLER

Figure 6. Frequency response setup.

Model8690B

Figure

7.

HP

8410A Network Analyzer

(110

MHz

to 12.4

GHz)

shown measuring phase and amplitude response

of

YIG

filter.

in

driving X-Y recorders, permitting recorder stabilization

before the initiation

of

the sweep· ramp. The B Model

8691 through 4 plug-ins incorporates the unique

HP

diode leveling capability, providing greater dynamic range.

Page 5

This enables

an

operator to reduce swept output signal to

a level that will not overdrive the 8410A Network Analyzer

system.

8706A

Control

Un

RF

Unit

Holder

The Hewlett-Packard 8706A Control Unit and 8707A RF

Unit Holder provide you with

an

inexpensive solution to the

need for broadband sweep capability.

The

Model 8706A

Control Unit substitutes for the normal RF unit in the

8690B Mainframe and

is

capable

of

programming up to

three 8707A RF Unit Holders, providing up to eight bands

of

frequency coverage from one

HP

8690B Mainframe. The

HP

8706A/8707A

is

described on page 10.

Applications

Literature

HP

Application Note 65, titled "Swept-Frequency Tech-

niques," provides

an

up-to-date discussion and error analysis

of

the most frequently used swept-frequency setups and

measurements techniques. Copies

of

Application Note

65

are available at all Hewlett-Packard field

offices.

Page 6

Mode!s

8691 8691

RF

U

(Installed

in

86908

Sweep

Oscillator)

Frequency Range

Frequency Accuracy

(at

max. leveled power)

Maximum

leveled

Power

RF

Power Control

< Frequency Stability

With

Temperature

[:

With

1

O%

Change

in

Line

Voltage

With

Power

level

Change

Residual

FM

(CW

mode)***

['. Power Variation, External

leveling**

f:•.

Output

Impedance

and/or

Connector

·I··

Pri~e

:·

1.·

Option

01. Internal Leveling

8691A

1 to 2

GHz

±1%

At

least 100

mW

BWOGrid

±

0.01%/"C

±500kHz

Typically <

20

MHz

(for

6

dB)'

<30kHz

peak

± 0.2 dB

50

ohms/Type N

$2,025.00

86918

1 to 2

GHz

±

10MHz

At

least 70 mW

Line

±

0.01%/oC

±500kHz

(for

10

dB)

<10kHz

peak

±

0.1

dB

50

ohms/Type N

$2,375.00

Model8690B

Power Variation

Equivalent Source Match

Price

± 0.4 dB

1.13:1

Add $315.00

1

Down

from max. leveled power.

Models

86928

100

RF

(Installed

in

86908

Sweep

Oscillator}

Frequency Range

Frequency Accuracy

(at

max. leveled power)

Maximum

leveled

Power

~F

Power Control

Frequency Stability

With

Temperature

With

10%

Change

in

Line

Voltage

With

Power

level

Change

Residual

FM

(CW

mode)***

Po~er

Variation, External

leveling**

Output

Impedance

and/or

Connector

Price

8692A

2 to 4

GHz

±1%

At least 70 mW

BWOGrid

±

0.01%/"C

±500kHz

Typically<

40 MHz

(for

6

dB)'

<30kHz

peak

±

0.2

dB

50

ohms/Type N

$1,825.00

8692B

2 to 4

GHz

± 20

MHz

At

least 40 mW

Line

±

O.Ol%/°C

±500kHz

±4MHz

(for

10 dB)

<15kHz

peak

± 0.1 dB

50 ohms/Type N

$2,175.00

8692B

Opt.

100

1.7 to 4.2

GHz

±

25

MHz

At least 15

mW

Line

±

0.01%/°C

±500kHz

±4MHz

(for

10 dB)

<20kHz

peak

±

0.1

dB

50

ohms/Type

N

$2,475.00

,

Option

01. Internal Leveling

Power Variation

Equivalent Source

Match

Price

± 0.4 dB

1.16:1

Add $315.00 1

Down

from max. leveled power.

Models

86938

100

RF

(Installed

in

869013

Sweep

Oscillator)

,',

Frequency

Range

Frequency Accuracy

(at

max. leveled power)

Maximum Leveled Power

RF Power Control

Frequency Stability

With

Temperature

With

10%

Change

in

line

Voltage

With

Power

level

Change

Residual

FM

{CW

mode)***

Power Variation, External leveling**

Output

Impedance

and/or

Connector

ji

.1'.-ice

I

,,

Option

01. Internal

leveling

Power Variation (into

matched

load)

Equivalent Source Match (approx.)

Price

8693A

4 to 8

GHz

±1%

At least

30

mW

BWO

Grid

±

O.Dl%/"C

±

lMHz

Typically <

SO

MHz

(for

6

dB)'

<50

kHz peak

± 0.2 dB

50

ohms/Type N

$1,625.00

± 0.5 dB

1.25:1

Add $350.00

86938

4 to 8

GHz

±

40MHz

At

least

15

mW

Line

±

o.01%/°C

±

lMHz

±

1MHz

(for

10 dB)

<15kHz

peak

± 0.1 dB

50

ohms/Type N

$2,025.00

± 0.4 dB

1.25:I

Add $350.00

86938

Opt.

100

3.7 to 8.3

GHz

±

45MHz

At least 5

mW

Line

± O.OI%fOC

±

lMHz

± 1 MHz

(for10dB)

<20kHz

peak

±

0.1

dB

50

ohms/Type N

$2,325.00

± 0.4 dB

1.25:1

Add $350.00

1 Down from max. leveled power.

*See page 8 for common specifications. **Excluding coupler and detector variation.

Model8690B Page 7

\)

Page 8 Model 8690B

Model8690B Page 9

Page 10 Model 8690B

DESCRIPTION

The

first simple

and

relatively

inexpensive

solution to

the

problem

of

broadband

sweep

capability (more

than

an

octave) is offered

by

Hewlett-Packard's

Model 8706A

Control

Unit

with

the Model 8707A RF Unit Holder.

When

used

with

the

HP Model 8690B

Sweep

Oscillator

and

appropriate

RF units, a compact,

bench-top

multi-

band

source

is formed.

The

Model

8706A Control Unit

with

its nine

band

selector

buttons,

replaces

the

usual

RF

unit

as a plug-in

for

the

sweep

oscillator mainframe.

It

supplies

power

for

and

controls

as

many

as

three

Model 8707A RF Unit

Holders,

each

of

which

accommodates

three

RF units.

Thus

it

is possible to

obtain

complete

frequency

cover-

age from 400

kHz

to 40 GHz

with

one easy-to-use sys-

tem.

Units

may

be

programmed

either

by

front

panel

con-

trol

unit

pushbutton

selection, or

sequentially

by

re-

mote

contact

closure to ground.

The

8706A also

can

provide

voltages

for

control

of

remote

circuits, relays,

etc. By utilizing

these

voltages to

program

a coaxial

switch,

for

example, you can

channel

the

output

sig-

nals

of

several

RF

units

through

a single

system

output

connector. Multi-band

tests

can

then

be

made

quickly

and

easily; changing RF unit3

and

cable

connections

is

handled

automatically

at

the

touch

of a

button.

Switching

time

between

bands

is one second,

with

no degradation of BWO life. This is

an

exclusive

new

accomplishment.

Two

separate

types

of

sweep

capa-

bility are available

in

each

band.

If

normal

sweep

is

selected

for

one

or

more

of the RF

units

in

the

8707A

RF Unit Holder, the

breadth

of the RF

unit

sweep

will

correspond

to

the

setting of the

start/stop

cursor

on

the

sweeper

mainframe-100%

if 0

and

100

are

select-

ed,

or

any

proportion

as designated

on

the

start/

stop

dial. A

second

preset

mode

is available for one

or

more

RF

units

by

pre-adjusting

start/

stop

frequency

settings

made

on

potentiometers

adjacent

to

each

RF

unit

plug-

in in

the

8707A RF Unit Holder.

Unnecessary

operation

of BWO

tubes

should

be

avoided

to

prolong

their

life.

At

the

same time,

it

is de-

sirable to

have

the

output

of

any

RF

unit

quickly avail-

able.

The

8707A

sweep

system

maintains

the

BWO's

on

standby,

removing

the

high voltage

when

not

in

use

to

extend

tube

life.

When

a single

band

is

not

to

be

used

over

some

period

of time, for example

during

a

laboratory

set-up procedure,

an

individual

RF

unit

may

easily be

turned

off, minimizing all aging effects.

Model 8690B

Page

11

Page 12

Model

8690B

Description

The

Hewlett-Packard

8698B RF Unit

for

the

HP

8690B

Sweep

Oscillator

covers

a

frequency

range

from

400 kHz

to 110 MHz

in

two

ranges.

The

all solid-state plug-in al-

lows

swept

measurements

to

be

made

easier

and

more

accurately

for

the

following

reasons:

Sweep

linearity

is

±0.5%

of

sweep

width

and

frequency

accuracy

of

the

start

and

stop

points

is

nominally

1%

of

frequency.

With

the

plug-in's high

linearity

and

frequency

accuracy,

the

operator

can

use

the

internal

graticule

markings

on

his

oscilloscope as a

frequency

scale

and

can

then

accurately

define

the

frequency

response

of

ampli-

fiers, filters,

and

other

devices.

Maximum

output

is

+13

dBm

(20

milliwatts) into a 50-

ohm

system.

Output

power

is

calibrated

in

10

dB

steps

from

+13

to

-110

dBm

with

vernier

adjustment

between

steps.

Calibrated

power

makes

it

easier

to define gain

and

loss

in

networks

and

amplifiers.

A built-in leveling circuit holds

the

output

flat

within

±0.3

dB

throughout

the

maximum

sweep

width,

providing

accuracy

in

measuring

a

device's

amplitude

response.

Residual

FM is

less

than

300 Hz on

the

0.4-

11 MHz

range

and

less

than

1 kHz

on

the

4-

110 MHz range,

assur-

ing clean,

stable

displays

when

testing

narrow

band

devices.

Harmonics

are

at

least

30

dB

down

and

spurious

re-

sponses

35

dB

down

over

the

entire

frequency

range.

There

are

many

convenient

sweep

functions: START-

STOP, MARKER SWEEP,

and

~F.

All

sweeps

are

cali-

brated

and

accurate.

The

8698B

can

be

voltage-programmed

in

both

ampli-

tude

and

frequency

and

is

capable

of

AM

and

FM.

Other

significant

features

are a

0.4-

11 MHz

auxiliary

output

which

allows

the

user

to

monitor

frequency

up to

110 MHz

with

an

11

MHz

counter

(such as

the

HP

5321),

a 5 MHz

crystal

calibrator,

an

uncalibrated

RF

output,

a

sweep

reference

output,

and

a 200.4- 310

MHz

VTO

output.

The

HP

8698B RF

Unit

is all solid-state

throughout,

in-

corporating

thin-film

microcircuit

amplifiers

in

its design.

Power

consumption

is

thus

held

low

and

reliability high.

Model

8690B Page 13

86988

Specifications

(Installed

in

8690B

Sweep

Oscillator)

FREQUENCY CHARACTERISTICS

Range:

Low

range, 0.4

-11

MHz; high range,

4-110

MHz.

Accuracy: (CW,

AF

center

frequency,

end

points

of

start-

stop

and

marker

sweep;

except

when

8690B is

in

Ext

FM mode.)

Low Range:

±1%

of

frequency

±50

kHz.

High Range:

±1%

of

frequency

±500kHz.

Linearity:

±0.5%

of

sweep

width.

Harmonics and Spurious Responses:

Non-Harmonics:

At

least

35

dB

below

CW

output.

Harmonics: (Output levels

below

+10

dBm)

At

least

30

dB

below

CW

output.

Residual

FM:

(CW

and

Sweep)

Noise

in

a 10 kHz

bandwidth

including line related

components:

Less

than

300 Hz rms,

low

range.

Less

than

1

kHz

rms, high range.

Combined

Incidental

and

Residual FM

with

internal

square

wave

modulation:

Less

than

600 Hz rms,

low

range.

Less

than

2 kHz rms, high range.

Residual AM: AM noise modulation

index

(rms, 10 kHz

bandwidth)

is less

than

-40

dB.

OUTPUT CHARACTERISTICS

Level:

+13

to

-110

dBm.

Output

is

calibrated

in 10

dB

steps

and

at

+13

dBm. Uncalibrated

vernier

provides

continuous

level settings over entire range.

Accuracy:

±1.5

dB

at

any

calibrated level.

Flatness:

±0.3

dB

over

full range.

Impedance:

50

n,

SWR

<1.2 on 0 dBm step

and

below.

RF

Leakage: Conducted

and

radiated

leakage limits are

below

those

specified in MIL-I-6181D.

SWEEP CHARACTERISTICS

(Operating

controls

are

located

on

the

8690B)

Start-Stop Sweep:

Sweeps

from

"start"

to

"stop"

dial

setting.

Marker Sweep:

Sweeps

from

"Marker

1"

to

"Marker

2"

dial setting.

In

both

Start-Stop

and

Marker

Sweep, dial settings are

continuously

and

independently

adjustable

over

the

en-

tire

frequency

range

and

can

be

set

to

sweep

either

up

or

down

in frequency.

AF

Sweep:

Sweeps

upward

in frequency,

centered

on

CW

dial setting.

AF

Width Accuracy:

Low Range:

±3%

of

sweep

width

or

±20

kHz, which-

ever

is

greater.

High Range:

±3%

of

sweep

width

or

200 kHz, which-

ever

is

greater.

Sweep Speeds: Continuously adjustable

in

four decade

ranges 0.01 to 100

seconds/sweep,

or

with

manual

con-

trol

from front panel, providing

continuous

tuning over

preset

limits.

Sweep Modes: Automatic [free running), line synchro-

nized,

or

triggered

by

either front

panel

pushbutton

or

external

pulse.

Sweep Indicator:

Front

panel

indicator lights during

sweep

duration.

MARKERS

(Controls

on

8690B)

Two

frequency

markers,

independently

adjustable

over

the

entire frequency range,

amplitude

modulate

the

RF

output.

Marker

amplitude is

adjustable

from

the

front

panel.

Marker Accuracy:

Low Range:

±1%

of

frequency

±50

kHz.

High Range:

±1%

of

frequency

±500

kHz.

Resolution:

Low Range:

±5kHz.

High Range:

±50

kHz.

Marker Output: Triangular pulse, typically

-5

V

peak

into 1

kO.

MODULATION

Internal AM:

Square

wave

modulation

continuously ad-

justable

from 950 to 1050 Hz. On-off ratio (level

vernier

in

calibrated position) is

20

dB.

External AM:

Bandwidth:

DC to

5kHz

at 30% modulation.

Sensitivity:

-10

V reduces RF

output

at

least

20

dB

(level

vernier

in

calibrated position).

IJ?.put

Impedance:

Approximately

1 kO.

External

FM:

(Sweep selector

in

"manual"

position)

Bandwidth: Deviations to

the

band

edges are possible

for

rates

to 100 Hz. Smaller deviations possible

at

rates

up

to

10 kHz.

Sensitivity: Deviation from

CW

setting is approximately

6%

of

frequency

band

per

volt.

CRYSTAL CALIBRATOR

Internal

5 MHz

crystal

allows

frequency

calibration to

±0.01%

at

any

5 MHz multiple using front

panel

fre-

quency

vernier.

AUXILIARY OUTPUTS

(Rear Panel)

Sweep Reference Output: Provides voltage analog

to

fre-

quency

output.

Approximately

1 V

/MHz

on

low

range,

1 V

/10

MHz

on

high range.

Uncalibrated

RF

Output:

-5

dBm minimum.

VTO Output:

-15

dBm minimum. 200.4- 310 MHz.

Auxiliary Output:

Always

0.4

-11

MHz, for

low

frequency

counter

monitoring.

GENERAL

Power: Supplied

by

HP 8690B

Sweep

Oscillator.

Weight: Net,

11lb

(5,0

kg). Shipping, 18 lb

(8,2

kg).

Dimensions:

41/z

in. wide,

71/4

in. high,

171/z

in. deep

(115

mm

x 185

mm

x 445 mm).

Price: Model 8698B, $1,550.00.

Options:

001:

75

n

output

impedance (BNC),

add

$50.00.

004: Rear

panel

RF output,

add

$75.00.

Page 14

e

ULTRA-BROADBAND-5

OCTAVES

e

ALL

SOLID

STATE

e

LINEAR

SWEEP

e

LEVELING/MODULATION

e

LOW

RESIDUAL

FM

e

LOW

SPURIOUS

CONTENT

e

ECONOMICAL

AND

CONVENIENT

The

Hewlett-Packard

8699B RF Unit is a completely

solid-state

0.1

to 4 GHz plug-in

unit

for

the

HP 8690B

Sweep

Oscillator.

It

is

extremely

versatile

and

can be

used

for a

wide

range of applications requiring an ac-

curate, stable, easy-to-use

swept

frequency

source.

BROAD FREQUENCY COVERAGE: Five octaves

of

frequency

coverage,

together

with

good stability

and

low

residual

FM, make the 8699B useful for testing

both

broadband

and

narrowband

devices.

With

this

single RF unit,

fast

and

accurate

swept

measurements

can

be

made

from VHF through S band, bringing con-

Model

8690B

venience

and

economy

to

lab

and

production

test

ap-

plications.

COMPLETELY SOLID-STATE:

Outstanding

per-

formance

and

high reliability

have

been

achieved

through state-of-the-art design

and

advanced

hybrid

integrated circuit technology.

The

result

is

broad

fre-

quency coverage

and

high

output

power

while fre-

quency stability

and

low

spurious

output

are

main-

tained. This completely solid-state RF

source

elimi-

nates

the

expense

of BWO replacement, resulting in

additional

operational

economies.

Model 8690B Page 15

8699B DESCRIPTION

Broad frequency coverage on the

0.1

to 2 GHz

band

is

achieved

with

a heterodyne design. The

output

of a

YIG oscillator,

tuned

from

2.3

to 4.2 GHz, is mixed

with

a fixed

2.2

GHz signal. The

0.1

to 2 GHz difference fre-

quency

is amplified

by

a broadband, thin film amplifier.

Undesired

higher order signals are eliminated before

the

amplifier

by

a

low

pass filter having a

sharp

cutoff

and

low

insertion loss

at

2.0 GHz.

The

thin film amplifier is

the

key

element in the

heterodyne

design. With over

40

dB

gain,

it

can de-

liver high

power

to the load while maintaining low

spurious

and

harmonic content. Even

at

maximum lev-

eled power, spurious outputs are below the level

where

they

would

affect

the

accuracy of most measurements.

A PIN modulator is

used

to control

the

output

of

the

2.2

GHz oscillator, thus providing

external

leveling ca-

pability

down

to 100 MHz. By placing

the

PIN modu-

lator before

the

mixer, spurious

output

is reduced

when

less

than

maximum leveled

power

is required.

Frequency pulling

with

level

or

load

change is

low

since the PIN modulator presents a

constant

load

to

the

2.2

GHz oscillator.

On the 2 to 4 GHz

band

the mixer

and

amplifier are

switched

out

of

the

circuit

and

the

YIG oscillator is

tuned

from 2 to 4 GHz. The PIN

modulator

remains in

the circuit for leveling

and

to provide AM modulation

capability. The inherent linearity of

the

YIG oscillator

results in a very linear

swept

output and leads to ac-

curate frequency displays on

both

bands.

Page

16

Model

8690B

8699B SUPPLEMENTAL OPERATING

INFORMATION

REMOTE PROGRAMMING:

For

digital programming

of

CW

frequency, a special

version

of

the

8690B

Sweep

Oscillator

is

available (8690B Opt. H26)

that

incorpo-

rates

a Digital-to-Analog

converter

and

accepts 12-line

BCD input.

MULTIBAND OPERATION:

When

the 8699B is in-

stalled

in

an

RF

Unit

Holder

(HP 8707

A)

and

the

HP

8706A

Control

Unit is used,

the

frequency

range

of

operation

must

be

selected

manually

with

the

switch

on

the

front

panel

of

the

8699B. To

switch

ranges re-

motely,

use

a modified

Control

Unit (8706A Opt. H25).

LEVELING:

With

a directional

coupler

and

crystal

detector,

the

power

variations

across

the

frequency

band

of

interest

will

depend

primarily

on

the

frequency

REAR PANEL CONNECTIONS

• EXT ALC GAIN:

Adjust

ALC gain

for

optimum

leveling across

the

band.

C) SWEEP REFERENCE OUTPUT:

Voltage

output

proportional

to RF frequency. Approxi-

mately

0 to

+40

V

output

on

2 to 4 GHz range only

(compatible

with

HP

8410A

Network

Analyzer).

There

is

no

output

on

the

0.1

to

2 GHz range.

response

of

the

coupler

and

detector

used.

An

alterna-

tive scheme,

useful

in

the

frequency

range

of

the

8699B,

is to

use

a

power

splitter

instead

of a

coupler

to

sample

RF

power.

With

this

technique,

the

maximum

leveled

power

available

at

the

output

will

be

lower,

but

overall

flatness will

be

improved.

EXTERNAL FM:

Modulating

signals

may

be

applied

to

either

the

front

panel

EXT FM

input

on

the

8690B

Sweep

Oscillator (with

the

SWEEP SELECTOR in

MANUAL)

or

to

the

rear

panel

PHASE LOCK

input

of

the

8699B.

For

best

performance,

the

latter

technique

should

be

used.

The

front

panel

EXT

FM

input

should

be

used

mainly

for

remote

frequency

control

or

for

modulation

at

wide

deviations

and

very

low

rates

(<1

kHz).

• REMOTE RANGE SELECT:

Permits remote range selection

by

a

contact

closure to

ground. A 3-prong

phone

plug

inserted

into

this

rear

panel

input

will disable the MANUAL range

switch

on

the

front

panel.

For

0.1 to 2 GHz, the plug tip is

grounded;

for

2 to 4 GHz,

the

tip is opened.

G PHASE LOCK INPUT:

Input

terminal

for phase-locking

control

voltage

or

ex-

ternal

FM signal. For phase-locking, the

input

sensi-

tivity

of

1

MHz/volt

is compatible

with

the

HP

8709A

Synchronizer.

For

FM modulation, Figure 8

shows

the

maximum

deviation

that

typically results

when

the

in-

put

level is

held

constant

and

the

modulation

rate

is

varied.

:!:30

N

J:

::2

z

0

[i

>

w

0

X

<!

::1:

::!:3

±I

1.0

MODULATION

RATE

(KHz)

Figure 8

For

more

information,

call

your

local

HP

Sales

Office

or

East

{201)

265-5000

•

Midwest

(312)

677-0400

•

South

(404)

436-6181

West

(213)

877-1282.

Or,

write:

Hewlett-Packard,

1501

Page

Mill

Road,

Palo

Alto,

California

94304.

In

Europe,

1217

Meyrin-Geneva

5952-0936

HP 86908 User manual

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