REFLECTOR-TYPE MICROWAVE ANTENNAS WITH ABSORBER LINED CONICAL FEED

摘要

A feed horn for a reflector-type microwave antenna comprises a smooth-walled conical horn and a lining of absorber material on the inside wall of the horn for reducing the width of the RPE (radiation pattern envelope) in the E plane of the antenna. The lining of absorber material extends from the wide end of the conical feed toward the narrow end thereof, terminating at a point where the horn diameter is about 7 times the longest wavelength of the microwave signals being transmitted. The width of the RPE in the E-plane of the antenna can be reduced to be nearly equal to the width of the RPE of the H-plane of the antenna without significantly degrading this H-plane RPE from its shape without absorber and without significantly changing the gain of the antenna.