A circular switched parasitic array antenna for high power data link applications

An enhanced circular switched parasitic array (CSPA) antenna is presented for a C-band data link application with high RF transmit power. Special requirements for the realized antenna gain are met by complementing the conventional CSPA configuration based on monopole antennas by an additional metallic top cover. The original ground plane and the top cover are shaped in such a way that a circular parallel plate waveguide with flared edges is formed resulting in an almost symmetrical radiation pattern with respect to the monopoles' ground plane. The loads of the parasitic monopoles are switched by means of surface-mount technology micro-relay switches in order to handle high transmit power. For post production compensation of manufacturing and component tolerances fine thread screws for mechanical adjustment are provided. Design and realization of a CSPA demonstrator antenna as well as measurement results are presented.