HORN-REFLECTOR MICROWAVE ANTENNAS WITH ABSORBER LINED CONICAL FEED

A horn-reflector antenna comprising the combination of a paraboloidal reflector forming a paraboloidal reflecting surface for transmitting and receiving microwave energy; a conical feed horn for guiding microwave energy from the focus of the paraboloidal reflecting surface to the reflector; and a lower end portion of the inside surface of the conical horn being formed by a smooth metal wall, the balance of the inside surface of the conical horn being formed by a layer of absorber material on at least the opposed side walls of said conical horn that affect the E-plane RPE of a horizontally polarized signal, the surfaces of the metal wall and the absorber material defining a single continuous conical surface, and the absorber material increasing the Eigen value E and the spherical hybridicity factor Rs sufficiently to cause the E-plane and H-plane RPE'S to approach each other. The exposed surface or the absorber material inside said conical feed horn is preferably substantially flat.