Rigorous design of an antenna for AUSSAT-B

The prototype antenna designed, constructed, and tested for the AUSSAT-B Western Australia regional beam has operated within specifications in all regards. More importantly, the overall design approach of using highly accurate software tools to obtain a successful first-time design has been vindicated. The antenna, comprising an array of horns illuminating an offset paraboloidal reflector, has a beamforming network (BFN) to provide correct power distribution and phasing to the feed elements. The antenna geometry is defined, showing the specified racetrack projected aperture. The other main constraint imposed on the antenna design was a volumetric limit on the feed and beamforming network. The far-field pattern obtained at 12.5 GHz is shown, with the beam pattern computed from measured BFN excitations superimposed. It is shown that the correspondence between theory and experiment is excellent.<>