K/Ka-Band Cylindrical Reflector Antenna for Compact Satellite Earth Terminals

A novel dual-band cylindrical reflector antenna with a hat feed is presented. A horn in a parallel-plate waveguide illuminates a parabolic surface to generate a TEM wave that is used to illuminate a corrugated feed. The feed is designed using a double step corrugation optimized to obtain good radiation patterns and good matching on the two bands of interest. The design of the grooves is based on the analysis of the radiation characteristics of the corrugated surface. In particular, the power re-radiated by the corrugation is considered to ascertain features which prove to be extremely useful in simplifying the design of the feed. The solution proposed in this communication makes possible to realize an antenna with compact size and low cost without sacrificing efficiency and compliance with radiation masks.