Array fed contoured beam antenna optimization with frequency variable excitations

Intelsat V, VI and VII spacecrafts use two separate array fed C-band antennas to provide Hemi and Zone contoured beams. The number of elements in the feed array is very large (140 for Intelsat VI). Complex beam forming networks (BFN) are used to generate required amplitude and phase excitations of the feed elements. We assess the possible performance improvement of an Intelsat-type of spacecraft antenna if the usual constraint for frequency invariant BFN excitations is removed. The physically realizability of the BFN excitations is also discussed. The Hemi-1 antenna is selected as the subject of this investigation.