A Lightweight, Low cost Spectrum Analyzer for Mobil Communications Applications

IFR Systems Inc.
Wichita, KS

A new spectrum analyzer has been introduced that has been specifically designed for mobile communications applications, such as service shops, basestation installation, repair and maintenance, and education. The model 2399 spectrum analyzer is lightweight and portable, and features rugged construction for use by engineers involved in field work. The new fully synthesized instrument operates over a frequency range from 9 kHz to 2.9 GHz, and features outstanding performance and a user friendly visual interface that simplifies many complex measurements.

With a weight of only 21 lbs (9.4 kg), the model 2399 is one of the lightest spectrum analyzers available today; a truly portable instrument that can easily go along to the job site or be equally at home on the test bench. However, performance has not been sacrificed in the process. The unit's local oscillator system is fully synthesized, providing accurate measurements within 1 Hz resolution, and the 6.4" TFT liquid crystal display provides a clear, bright and sharp full color image with a 640 X 480 pixel active display area that is viewable in high ambient light conditions.

Ease of Measurement
Specifically targeted to communications applications, the instrument includes semi-automated routines to measure adjacent and main channel powers, as shown in Figures 1 and 2, respectively,

as well as occupied bandwidth, harmonic distortion and power levels below the carrier. A single button initiates the measurements and the results are displayed in a table listing, in the harmonics analysis case, the frequency and level of each harmonic plus the total harmonic distortion of the measured signal. The instrument's internal processor is extremely fast and contains a large memory capable of storing up to 1000 screen traces and 2000 operational states.
An elaborate marker system, as shown in Figure 3,

permits as many as nine markers to be displayed simultaneously with a marker table indicating the frequency and level of each individually selected marker. The new analyzer also provides delta markers, peak track, 1/delta, marker-to-center and marker-to-reference capabilities. Figures 4, 5 and 6

show screen shots of occupied bandwidth, harmonic distortion and X dB down measurements, respectively.
In addition, the 2399 spectrum analyzer has outstanding phase noise characteristics at -90 dBc/Hz at 10 kHz offset from the carrier. Coupled with a wide dynamic range that accepts signals of +30 to -110 dBm with up to 50 V DC input protection at the 50 W input port, the new analyzer has not compromised on performance or capability.

The 2399 portable spectrum analyzer is supplied with a floppy disk drive and an extremely user friendly man-machine interface that reduces operator error. As a result, extremely complex measurements can be made simple and easy. An optional full-range tracking generator allows mixer and signal converter measurements to be made directly, and an auto tune function is available.

Special Functions

Special measurement functions help to make complex analysis easy to perform. The limits facility permits an upper and/or lower limit to be set on the screen. If the displayed input signal falls outside either limit a message appears on the screen indicating the limit has been exceeded and how many times it has occurred. The auto tune function allows an unknown signal to be captured and displayed. The 2399 analyzer searches its complete frequency range for the highest level signal, captures it and displays it in the center of the screen with the span and resolution bandwidth automatically set to provide optimum viewing.

The instrument is also capable of demodulating both AM and FM signals for a wide range of communications applications. The demodulated signal can then be displayed on the screen and is available on an internal speaker and on headphones via a front panel connector. In addition, the modulation depth may be measured by means of internal markers.

Data interfaces for the 2399 unit include IEEE 488-2, RS 232 and a PCL5 printer port, thereby permitting the instrument to be integrated in various automated test systems. The analyzer's operating system and its memory have the capability to have additional facilities incorporated for greater flexibility and future expansion.


The new 2399 portable spectrum analyzer offers the performance and capabilities of a full function instrument in a lightweight, rugged portable package that is ideal for personnel involved in the service, installation and maintenance of wireless communications equipment and systems, while providing an excellent, low cost instrument for laboratory and automated production test applications as well. The new instrument offers excellent performance at a reasonable price ($9600 for the basic instrument). In addition, product upgrades will be made available over time that will offer new software modules targeted at key applications. Additional information may be obtained from the company's Web site at www.ifrsys.com or via e-mail at info@ifrsys.com.

IFR Systems Inc.,
Wichita, KS (316) 522-4981 or (800) 835-2352.

Circle No. 304