Airborne Dual Antenna System for Aerial Navigation

This paper describes a 1000-mc dual antenna system which uses parallel-driven sector antennas. Methods for determining the performance in pattern interference regions are given together with applications to DME, Radar Safety Beacon and TACAN navigation systems. A flyable-model dual antenna system for Constellation and DC-6 type aircraft is described. Provision of an RF hybrid permits the simultaneous operation of two navigation equipments, such as DME and Radar Safety Beacon, from the same antenna system. A prototype of this antenna system on a DC-3 has provided improved performance for the TACAN navigation system. Flight tests with an experimental dual antenna system have shown improved performance for DME and Radar Safety Beacon systems. The results of flight tests show agreement with theoretically determined values of performance.