Horn-reflector microwave antennas with absorber lined conical feed

摘要

A horn-reflector antenna comprising the combination of a paraboloidal reflector (11) forming a paraboloidal reflecting surface for transmitting and receiving microwave energy; a conical feed horn (10) for guiding microwave energy from the focus of the paraboloidal reflecting surface to the reflector (11); and a lower end portion (10a) of the inside surface of the conical horn (10) 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 (30) on at least the opposed side walls of said conical horn (10) that effect the E-plane radiation pattern envelope (RPE) of a horizontally polarized signal, the surfaces of the metal wall (10a) and the absorber material (30) defining a single continuous conical surface, and the absorber material (30) 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 (30) inside said conical feed horn is preferably substantially flat.