Land-mobile Ka-band satcom tracking antenna employing a printed circuit board based multimode monopulse feed

The growing interest in bi-directional mobile satellite communications in Ka-band necessitates the development of dedicated antenna systems and feeds. In this paper we describe a mobile satellite communications ground terminal with a Cassegrain reflector antenna fed from a multimode monopulse tracking system for circular polarisation at the satellite downlink frequency of 20 GHz. The novel structure based on transitions from coplanar to circular waveguides is operational at 30 GHz as well, to cover the uplink frequency range. The antenna system is mounted on a high-performance mechanical positioner to facilitate a fast and precise compensation of the movements of the carrier vehicle. This work contributes to the development of a satellite terminal for land-mobile communications in disaster scenarios [1].