Patent ID: 7242904
Filing Date: 2007-07-10
Classification: H01Q

Abstract:
1. A multiple beam antenna system on a communications satellite comprising: a set of reflector antennas that shares transmit and receive band frequencies; a plurality of dual-band frequency-dependent feed horns for feeding said set of reflector antennas and generating a cell reuse pattern on the ground; a phase center for said transmit frequency band located a predetermined distance in an aperture of a horn in said plurality of horns; a focal point for a reflector in said set of reflector antennas that coincides with said phase center for said transmit frequency band: a phase center for said receive frequency band located a predetermined distance from said phase center for said transmit frequency band in said aperture of said horn to defocus said receive frequency band for the purpose of under illuminating said reflector at uplink frequencies; whereby said plurality of feed horns illuminates said reflector optimally at downlink frequencies and under illuminates said reflector at uplink frequencies.