High end microwave technologies in global communications

Microwave technologies for communication satellites are examined. Microwave technology advances are currently addressing a number of telecommunication issues, including radio spectrum conservation, increased capacity and capacity flexibility, lower costs, and new services such as ISDN and B-ISDN (broadband integrated services digital network). The generic microwave solutions are frequency reuse, increased G/T and EIRP (equivalent isotropically radiated power), lighter weight, and various forms on onboard processing. Specifically, the microwave components include advanced multibeam antennas, shaped-beam antennas, shaped reflector antennas, active phased array fed and direct radiating antennas, MMIC (monolithic microwave integrated circuit) beamforming networks, microwave switch matrices, and solid-state power amplifiers. Two examples of high-performance microwave hardware are presented, one using passive circuits and one with active circuits, i.e. microwave filters and active phased array antennas. It is concluded that much work remains to be done in microwave circuits to help the competitiveness of the communications satellite industry. Larger numbers of satellites and array antennas are only two drivers for designs that are realizable without tuning or ´tweaking´, thereby reducing the cost.<>