A COMPACT OFFSET GREGORIAN ANTENNA SYSTEM FOR PROVIDING ADJACENT, HIGH GAIN ANTENNA BEAMS

摘要

An antenna system comprising a feed array, a subreflector and a main reflector which are oriented to define a offset gregorian antenna geometry. The feed array is comprised of a plurality of separate feeds which are aligned o n a predetermined contour. Each feed array is coupled to a feed network which ac ts to combine the illumination beams of clusters of a preselected number of fee ds to produce a plurality of composite illumination beams. Each composite illumination beam is directed to be incident upon a separate predetermined location on the subreflector which directs the composite illumination beams and directed towards the main reflector. Each composite illumination beam is reflected by the main reflector in a preselected direction so that each composite illumination beam forms an antenna beam that impinges a predetermined coverage area on the Earth. Each antenna beam defines a separate coverage cell in the coverage area, wherein the position and orientation of the feeds , the subreflector and the main reflector provides antenna beams over a full Earth field of view coverage area where each antenna beam is approximately symmetrically shaped.