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Industry News

A High Speed Radio Communications Analyzer

This month's cover features a radio communications analyzer that is capable of performing the same functions as a full rack of test equipment with greater speed

April 1, 1997
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A High Speed Radio Communications Analyzer

Anritsu Wiltron Co.
Morgan Hill, CA

Speed and flexibility are increasingly crucial requirements of test instruments used by cellular handset manufacturers. The ability to test thousands of handsets -- based on multiple standards -- in as little as an hour is now the rule, not the exception. The model MT8801B radio communications analyzer meets this new manufacturing challenge, performing dozens of tests in less than two seconds based on current digital cellular standards.

All analog and digital transmitter and receiver parameters of the IS-136A, Global System for Mobile communications (GSM), digital communications system (DCS) 1800, personal communications service (PCS) 1900, personal handyphone system (PHS) and personal digital cellular (PDC) standards can be evaluated using the MT8801B. The analyzer achieves this capability by fully integrating the functionality of eight pieces of test equipment into one instrument as well as utilizing unique measurement algorithms, and leading-edge digital signal processing and application-specific IC technology. The result is a single instrument that performs the same functions as a full rack of test equipment with greater speed.

Essentially, the MT8801B is eight instruments in one: a cellular/PCS base station simulator, 3 GHz RF spectrum analyzer, digital modulation analyzer covering 300 kHz to 3 GHz, audio analyzer/generator, analog modulation analyzer, digital modulation analyzer with less than or equal to two percent error, power meter with built-in thermocouple sensor and bit error rate tester. The analyzer's typical output screen displaying an 835 MHz modulated signal is shown in Figure 1 .

Fig. 1 The analyzer's typical output screen.

Software is the key to providing the MT8801B with its multiformat flexibility. Specific options are available for each of the digital cellular standards, allowing manufacturers to customize the radio communications analyzer for weekly, daily or even hourly testing requirements. Additional standards are added easily with a simple software upgrade. By combining software flexibility and fully adjustable frequency settings, the MT8801B can measure cellular and PCS signals, as well as everything in between.

Users can switch from one cellular standard to another simply by pressing a few buttons on the user-friendly faceplate. In less than a minute, the instrument can change from testing phones based upon IS-136A testing to GSM, DCS1800, PCS1900, PHS or PDC. Because the format change is made quickly, manufacturers can complete the change during a break or shift change, eliminating downtime. The analyzer also allows for dual-mode and dual-band testing to be performed with one instrument.

All IS-136A and GSM/PCS1900/DCS1800 call-processing functions, registration, origination, termination, communication, handover, disconnect from network and disconnect from mobile station tests can be performed with the MT8801B. The radio communications analyzer also generates the burst-wave signals necessary for reception sensitivity measurements from either loopback methods or the measurement signal report received from the mobile station.

Among the other tests the MT8801B can perform in less than two seconds are adjacent-channel power, occupied bandwidth, origin offset, frequency and frequency error, leakage power during carrier off, modulation accuracy and antenna power. These parameters may be measured and reported as actual data, or preset go/no go conditions may be used for high speed manufacturing lines. Full support for performing 800 to 1900 MHz base station handoffs is standard. Table 1 lists the analyzer's key performance specifications.

Table I: Key Performance Specifications

Frequency range (MHz)

0.3 to 3000

Maximum input level (dBm)

+40 (main connector)

Power meter
range (dBm) accuracy after
zero calibration
maximum dynamic
range (dB)

0 to +40
±10 %
96

Signal generator
frequency
resolution (Hz)
output level (dBm)

1
-143 to -28
(main connector)

Modulation analyzer

FM, PM,
pi/4 DQPSK, GMSK

Audio generator/
analyzer (Hz)

30 to 20,000

Spectrum analyzer

full feature 3 GHz,
with sweep
and marker functions

Systems supported

IS-136A/GSM/
PCS1900/DCS1800/
PDC/PHS

Display

color LCD, 7.8 inches,
640 × 480 dots

Interfaces

GPIB, parallel
(Centronics),
RS232C, DUT

The MT8801B is efficient at performing tests that traditionally required eight instruments. Rather than having a rack filled with eight separate instruments that perform different tests, eight MT8801Bs can be installed in the rack, allowing eight times as many handsets to be tested in the same space. When this capability is coupled with the radio communications analyzer's 1.8 s measuring time, countless time is saved.

Inter-instrument connections are not needed with the MT8801B, eliminating a possible cause of inadequate measurement performance due to faulty cables connecting the instruments. Additional time is saved because only one instrument must be recalibrated each time testing parameters change. With the MT8801B, accurate calibration is assured through the sensor within the power meter. This sensor calibration guarantees the accuracy of the average power amplitude measurement during burst on. Both general-purpose interface bus (GPIB) and RS-232C interfaces are standard, allowing the radio communications analyzer to be operated remotely and have data downloaded to a PC. The interfaces allow the MT8801B to be integrated into automated test system applications easily. A standard DOS-compatible 3.5" disk drive is used to install firmware and upgrade the MT8801B. Results are read easily on a full-color display.

The analyzer's price depends on configuration. The base price is $45,000 and available options range from $2300 to $5500. Delivery: eight to 10 weeks (ARO).

Anritsu Wiltron Co.,
Morgan Hill, CA (408) 776-8300 or http://www.anritsuwiltron.com.

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