Atec Agilent-8901B User Manual

HP 8901B Modulation Analyzer

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Options 030/037

10 MHz - 1.3 GHz

Technical Specifications

Selective Power Measurements

Adjacent Channel Power
Measurements

The HP 8901B Modulation Analyzer’s easy-to-usese­lective power measurement option saves you time
and money, speeding adjacent-channel power testing
on your RF communications transmitters. These se­lective measurements meet the stringent CEPT stan­dards for adjacent-channel power with superb accu­racy: ±0.5 dB; dynamic range >115 dB; and selectivity
>90 dB. The HP 8901B also performs RF power, fre­quency, modulation and audio measurements, plus
selective RF power measurements, fully characteriz­ing your transmitter in seconds.

Making an adjacent channel power measurement is
simple. You first select the appropriate filter
(12.5, 25 or 30 kHz channel spacing) and measure the
transmitter carrier power. Then, tune the analyzer to
any offset desired, and measure the channel power.
The analyzer displays the results in dBc (dB relative
to the carrier power).

To meet the CEPT noise-floor requirements at fre­quencies greater than 300 MHz, the HP 8901B re­quires an external local oscillator (LO) such as the
HP 8656B Synthesized Signal Generator. Selecting
an external LO with fine frequency resolution also
improves the analyzer’s tuning resolution, which can
be as coarse as 2 kHz at 1300 MHz. Using an
HP 8656B signal generator gives you 10 Hz resolution
up to 990 MHz. Dedicating a signal generator as the
external LO is not necessary. When not being used as
the LO, a built-in RF switch in the HP 8901B routes
the signal generator’s output to the rear panel of the
analyzer.

HP-IB: Not just IEEE-488, but the hardware
documentation and support that delivers the
shortest path to a measurement system.

Direct-Spectrum Carrier Noise
Measurements

The HP 8901B Modulation Analyzer, with a low noise
external LO, performs fast, accurate single- sideband
(SSB) carrier noise measurements to 1.3 GHz. To
make a carrier noise (AM noise and phase noise)
measurement, you select the noise filter
(2.5 kHz noise bandwidth), measure the source un­der test’s carrier power, tune the analyzer to the fre­quency offset desired (5 kHz to 1300 MHz) and mea­sure the noise. The data is displayed in real time,
either as dBc in a 1 Hz bandwidth or as total power
in the 2.5 kHz filter bandwidth.

Direct-Spectrum Carrier Noise
Measurements (cont’d)

Phase noise usually dominates the carrier-noise
measurement at most offsets of interest, so
direct-spectrum noise measurements provide a con­venient and simple way to measure phase noise of
many sources. This measurement technique is rela­tively insensitive to many common pitfalls encoun­tered in making phase noise measurements. There is
no need to phase-lock signals. Testing can be fully
automated using an external controller. Most impor­tant, selective signal and noise measurements are
fast (five readings/second). The analyzer’s measure­ment accuracy is better than ±0.5 dB to –129 dBc/Hz,
typically better than ±1 dB to –140 dBc/Hz. The noise
floor is –150 dBc/Hz.

Many applications require spectral purity to be ex­pressed as residual AM, FM or phase modulation.
With the HP 8901B’s convenient modulation capabili­ties you make these measurements with one key­stroke, in a variety of common bandwidths.

To extend the measurement range to 26.5 GHz, add
the HP 11793A Microwave Converter and a low noise
microwave source, such as the HP 8673B Synthesized
Signal Generator. With this system you can test high­performance sources from 10 MHz to 26.5 GHz.

Block Diagram

The high-selectivity option for the HP 8901B Modu­lation Analyzer adds an RF switch, a buffer ampli­fier, variable gain IF amplifiers, narrowband filters
and a rms detector. To make selective power meas­urements, the analyzer mixes down the RF input sig­nal using either the internal LO or an external LO.

The IF signal is buffered and sent through one of two
narrowband bandpass filters which provide over 90
dB of rejection. The signal is amplified by precision
IF amplifiers, filtered again and measured by the rms
detector. The IF amplifiers provide as much as 95 dB
of gain in 5 dB increments; the rms detector is used
over a 20 dB dynamic range.

Specifications

All parameters describe performance in automatic
operation or properly set manual conditions.

Specifications describe’s the instrument’s
warranted performance.

Supplemental Characteristics (shown in italics)
are intended to provide information useful in apply­ing the instrument by giving typical, but non­warranted, performance parameters.

FREQUENCY RANGE:

CARRIER POWER RANGE:

DYNAMIC RANGE:

CARRIER REJECTION (Temp 35

10 MHz to 1300 MHz.

+30 dBm to –20 dBm; 12.5 kHz, 25 kHz
and 30 kHz filters.
+30 dBm to –10 dBm; carrier noise filter.

115 dB

o

>90 dB; for offsets of at least 1 channel spacing
or 5 kHz, whichever is greater.

C):

RELATIVE MEASUREMENT ACCURACY:

±0.5 dB; levels ≥ –95 dBc; 12.5 kHz, 25 kHz and

30 kHz filters.

±0.5 dB; levels ≥ –129 dBc/Hz; carrier noise filter.

CARRIER NOISE FILTER

Filter Noise Bandwidth: 2.5 kHz nominal.
Noise Bandwidth Correction Accuracy (stored

in non-volatile memory): ±0.2 dB.

Supplemental Characteristics:

ADJACENT/ALTERNATE CHANNEL FILTERS
6 dB Filter Bandwidth:

8.5kHz, 12.5kHz adjacent-channel filter.

16.0 kHz, 25 kHz adjacent-channel filter.

30.0 kHz, 30 kHz (cellular radio) alternate­channel filter.

TYPICAL NOISE FLOOR: – 150 dBc/Hz, 0 dBm carrier

power level. For System noise performance add LO
contribution.

ALL OTHER HP 8901B SPECIFICATIONS ARE
UNCHANGED.

Ordering Information

HP 8901B Modulation Analyzer

Option 030: High Selectivity

(Option 030 includes rear-panel
external LO connections.
HP 8901B Option 003, Rear-Panel
External LO Connections, may not be
ordered with HP 8901B Option 030.)

Filter Options

(Select only two filter options.)

Option 032: 12.5 kHz Adjacent Channel Filter

Option 033: 25 kHz Adjacent Channel Filter

Option 035: 30 kHz (Cellular Radio) Alternate

Channel Filter

Option 037: Carrier Noise Filter

For more information about Hewlett­Packard test & measurement products,
applications, services, and for a current
sales office listing, visit our web site,
http://www.hp.com/go/tmdir.You can
also contact one of the following centers
and ask for a test and measurement sales
representative.

United States:

Hewlett-Packard Company
Test and Measurement Call Center
P.O. Box 4026
Englewood, CO 80155-4026
1- 800-452-4844

Canada:

Hewlett-Packard Canada Ltd.
5150 Spectrum Way
Mississauga, Ontario
L4W 5G1
(905) 206- 4725

Europe:

Hewlett-Packard
European Marketing Centre
P.O. Box 999
1180 AZ Amstelveen
The Netherlands
(31 20) 547 9900

Japan:

Hewlett-Packard Japan Ltd.
Measurement Assistance Center
9-1, Takakura-cho, Hachioji-shi,
Tokyo 192, Japan
(81 426) 56 7832
Fax [phone]

Latin America:

Hewlett-Packard
Latin American Region Headquarters
5200 Blue Lagoon Drive
9th Floor
Miami, Florida 33126 U.S.A.
[phone]/4220

Australia/New Zealand:

Hewlett-Packard Australia Ltd.
31-41 Joseph Street
Blackburn, Victoria 3130
Australia
1 800 629 485

Asia Pacific:

Hewlett-Packard Asia Pacific Ltd.
17-21/F Shell Tower, Times Square,
1 Matheson Street, Causeway Bay,
Hong Kong
(852) 2599 7777
Fax: [phone]

Data subject to change
©Hewlett-Packard Company 1997
Printed in U.S.A. 2/97

5953-8424E