Design of a Compact Steerable Reflector Antenna at Ka-Band in Axially Dispaced Ellipse Geometry

Design of an electrically smaller diameter reflector antenna (diameter < 50λo) is a challenging task because the overall reflector efficiency is reduced by the higher percentage blockage due to sub-reflector, its support structure and the feed system. The reflector has to be mounted on a mechanically steered platform and support dual circular polarized operation on a satellite. These requirements added further to the design complexity. This work provides a good working design of a 0.35m diameter reflector antenna in Axially Displaced Ellipse (ADE) geometry and its feed at Ka-Band for transmitting high throughput payload data to the ground stations. Realized efficiency is more than 50% with cross-polar isolation better than 30dB.