Stepped-Reflector Antenna for Dual-Band Satellite Communications Payloads

This paper presents a novel stepped-reflector antenna (SRA) suitable for multiple beam dual-band satellite communications. The SRA generates "flat-top" receive beams and highly efficient transmit beams over a geographic coverage region as seen by the satellite. It combines the reflector improvements through the use of stepped-regions with the feed horn advancements through the use of dual-band high efficiency horns (DBHEH) to realize an efficient multiple beam antenna (MBA) system supporting both uplink and downlink frequencies simultaneously. It is shown that the SRA provides a congruent set of spot beams at both frequency bands with the benefits of significantly improved edge-of-coverage (EOC) gain, improved copolar isolation (C/I) among re-use beams, receive beam patterns that are less sensitive to pointing errors, and reduced number of reflector antennas when compared to conventional MBAs