A high performance dual-band communication and RF sensing feed system for DBS

A high-performance dual-band communication RF sensing feed has been developed for use in a dual-offset reflector configuration. The components in the overall feed chain, including the corrugated horn, tracking coupler and external waveguide network, polarizer, and multiplexer are described, and the measured performances of the full development model are presented. This performance, which significantly advances the state of the art, includes low loss feed and circularly symmetric beams with low sidelobe levels and low levels of cross-polarization in two discrete but widely separated communication bands. The feed also provides the sum and two difference error levels. High levels of mode coupling combined with high isolation between sum and difference and difference-to-difference signals are demonstrated. The use of a single feed system for multifunction operation leads to considerable savings in size and cost of spacecraft payloads without sacrificing performance.