Effect of Guard Band Reduction on Marker Beacon Receiver Performance
FEDERAL AVIATION ADMINISTRATION TECHNICAL CENTER ATLANTIC CITY NJ
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Aircraft Marker Beacon Receivers, which are a part of the Instrument Landing System, operate at a frequency of 75 megahertz MHz and until January 1, 1990, were protected by a guard band of - 400 kilohertz kHz. After this date, the guard band was reduced to - 200 kHz. This report details testing performed at the Federal Aviation Administration FAA Technical Center to assess the effect emitters, using this new guard band, will have on Marker Beacon Receivers. The effect of the interference on the Marker Beacon Receivers was determined by performing a desensitization test, a no-desired signal test, and a selectivity measurement on five general aviation Marker Beacon Receivers. For these tests, emitters that use amplitude modulation, frequency modulation, pulse modulation, and continuous wave were simulated. It was found that emitters using these new frequencies can cause interference to Marker Beacon Receivers. Recommendations for limiting the interference effect are provided in the body of the report.
- Air Navigation and Guidance
- Radiofrequency Wave Propagation