Phased-array-fed dual-reflector antennas

Two novel antenna configurations of dual reflecting surfaces with a phased-array feed are examined for limited scan applications. Their advantages and limitations are discussed. The first one, a bicollimaged dual-reflector antenna, is similar to a classical confocal reflector, but its main and subreflectors are specially shaped so that it can collimate the main beam in two directions instead of one and have a better scan capability. The second configuration, a converging-array dual reflector, consists of a parabolic main reflector and an elliptical subreflector. This configuration requires a smaller subreflector and array feed for a given scan range, but requires more complicated feed control.