A limited electronically scanned Cassegrain antenna at Q-band

A unique limited scan satellite antenna at Q-band (44GHz) is described. The configuration presented is a conventional Cassegrain reflector systefme d by an electronically scanned phased array with a dielectric "field lens" between the array and the subreflector. The purpose of this field lens is to reduce the scan loss of the single scanned beam as compared with other limited scan configurations. A mall 18 inch diameter proof-of-concept (PoC) model was designed, built and tested. The measured performance of the model agreed quite well with computer calculated patterns and it is therefore felt that calculated predictions of a full scale model would also be accurate.