Maintenance Test Station (MTS)
Communications & Embedded Systems
AN/FPS-85 Radar Site
Transmitter Calibrator Monitor Unit
The AN/FPS-85 (a computer-controlled, phased-array radar) searches, detects, identifies, and tracks satellites and other space objects. Built in the 1960s, this unique high-power radar is at Eglin Air Force Base in Florida.
The AN/FPS-85 radar incorporates separate transmitter and receiver arrays operating at 442 MHz. The Transmitter Array System is composed of 5,184 radar transmitter units arranged in a 72-square matrix. Each radar transmitter unit delivers nearly 10 kilowatts of peak power into a dipole antenna yielding a collective beam peak power of more than 30 Megawatts.
During this program, Southwest Research Institute (SwRI) designed and developed the maintenance test station (MTS) used to test the recently SwRI-designed transmitter units. SwRI selected a modern suite of automated test equipment (ATE) and developed custom software using the Labview® development platform. The MTS was designed to fulfill not only the long-term transmitter maintenance requirements of the site, but also to serve as the production test station (PTS) for acceptance testing of each upgraded transmitter unit.
Maintenance Test Station/Production Test Station
The Maintenance Test Station/Production Test Station included a(n):
- Radio frequency power meter (with pulse and CW sensors)
- Spectrum analyzer
- Oscilloscope
- Vector voltmeter
- Multimeter
- Arbitrary waveform generator
- Custom RF signal sources (14.7 MHz, 85.3 MHz, 537–547 MHz, 437–447 MHz)
- Synthesized AC power supply (117 VAC 60 Hz)
- High-voltage power supply (5.5 kVDC)
- High-voltage pulsed supply (1 kV, 5–255 ms, 1% duty)
- Switch matrix (48x4), a touch-screen color monitor
- Computer (with GPIB and Digital I/O boards)
- Printer
- Transmitter test fixture
- RF coaxial switches
- RF envelope detector
- RF distribution tree (signal splitter)
The software included:
- Automated transmitter tests
- Automated test station self-tests
- Manual operating mode
A detailed report and historical record is produced for each transmitter tested. The self-test includes calibration of the test setup for losses and signal levels. A full calibration and self-test includes 289 individual tests and takes about 50 minutes to run. An abbreviated calibration limited to the essential parameters is available and can be run in about 15 minutes.
The transmitter test sequence includes 137 individual tests and takes about 30 minutes for a production acceptance test. A test configuration utility allows test groups to disable during maintenance to reduce test time. The most basic operational transmitter test sequence can be run in a few minutes.
Related Terminology
communication networks • maintenance test station • AN/FPS-85 • transmitter array system • radar systems • communication systems • automated test station self-tests • custom software development • communications engineering
