Development and measurements of the TM/TC antenna for the DFS satellite

The design of the S-band telemetry/telecommand antenna, which is to operate in the S-band from 2-2.3 GHz, is described. The configuration of the four radiation elements needed to obtain coverage for the antenna in the range theta not greater than 120 deg and phi = 0.360 deg is discussed. The use of a stripline hybrid network to establish circular polarization is examined. The performance of an antenna model mounted on a telescopic boom and attached to a model of the German Communication Satellite DFS is evaluated at two frequencies for each configuration. The data reveal that the antenna's performance is uniform radiation in the phi plane, broadband characteristic, and displays identical patterns for right hand circular and lift hand circular polarizations.