A dual-offset reflector with a foam dielectrics cone feed and a shaped subreflector is described. The antenna is designed to receive signals from direct broadcast satellites. It combines a compact design with a relatively high efficiency and low sidelobes. The paper describes the theoretical design procedure, including the shaping of the subreflector which corrects for distortions introduced by the dielectric cone. A 12 GHz model is described which has been built and successfully tested.

A study of a compact dual-offset reflector antenna with a low-permittivity dielectric cone between a simple feed and the subreflector is reported. The antenna is analysed using a combination of modal field analysis and geometric optics. An experimental model has been constructed and measured in order to verify the theoretical analysis. A parametric study of the antenna is described. The performance of the antenna makes it suitable for use as a small earth-station antenna.