UHF satcom antenna architectures

Future UHF satellite development will require design and requirements attention to space segment antennas. Multiple beam UHF antennas are addressed for geosynchronous orbits. These antennas are significantly impacted by the large UHF percentage bandwidth and by their large size. While microwave systems can generally accommodate separate receive and transmit apertures, the overall size of UHF high gain antennas provides design and integration challenges. While increased capacity is desired to meet future mission objectives, traditional microwave approaches such as frequency reuse and multiple beam antennas, are limited by the relatively high margins needed to provide reliable communications to system users. The system issues underlying future UHF satellite antenna selection are described.