Folded horn-reflector antenna wherein primary reflector is nonreflective at portion where specular reflection to feed would otherwise occur

Claim 1

AN ANTENNA WHICH COMPRISES, A TRUNCATED FEED HORN, A MIRROR-LIKE REFLECTING SURFACE AT THE PLANE OF TRUNCATION OF SAID HORN, A CURVED PRIMARY REFLECTOR SPACED FROM SAID REFLECTING SURFACE ALONG THE LONGITUDINAL AXIS OF SAID FEED HORN, AND APERTURE IN SAID PRIMARY REFLECTOR AT THE INTERSECTION OF THE AXIS OF SAID FEED HORN THEREWITH WHEREBY THE EFFECTIVE APEX OF SAID HORN AND THE FOCUS OF SAID PRIMARY REFLECTOR COINCIDE AT A POINT AND THE FOCUS OF SAID PRIMARY REFLECTOR REMOTE FROM SAID REFLECTING SURFACE, AN APERTURE IN SAID MIRROR-LIKE REFLECTING SURFACE SUBSTANTIALLY ON THE AXIS OF SAID HORN, THE APERTURE AREAS IN SAID PRIMARY REFLECTOR AN IN SAID MIRROR-LIKE REFLECTING SURFACE BEING SMALL AS COMPARED WITH THE AREAS OF SAID CORRESPONDING REFLECTING SURFACES, AND MEANS COUPLED TO SAID APERTURE IN SAID MIRROR-LIKE REFLECTING SURFACE FOR DISSIPATING ENERGY INCIDENT ON SAID APERTURE.