RECONFIGURABLE MULTIBEAM ANTENNAS FOR SATELLITE COMMUNICATIONS.

A review is presented of the design problems associated with multibeam antennas and gives results based on some original work. Starting from a summary of desirable characteristics four areas of concern are defined and discussed: beam topology, microwave optics, radiating elements and beamforming network. On the basis of detailed computer analysis a reconfigurable antenna was designed using 144 component beams for seven independent shaped beam coverage of the world. The implementation employs an offset fed paraboloid, multimode radiating elements and variable stripline beamforming network. Theoretical and some experimental results are given.