Abstract: A monopulse radar antenna having an improved three-channel feedhorn for piding selectable polarization and greater target discrimination. The antenna feed employs a comparator having a difference port, a first sum port, and a second sum port utilizing a coupling pin or probe therein, between the comparator ports and an adjustable polarization device, for receiving and separating returned energy which has become cross-polarized with respect to the polarization of the transmitting sum arm, by reflection from an asymmetrical target. The three-channel feedhorn makes possible the identification of different types of targets, and the detection of hidden targets in rough terrain, forests, underbrush, and rough seas.

Abstract: A rotatable radar antenna feed and receiver horn having two summing ports d a difference port with a rotatable section having a plurality of susceptor pins to rotate the polarization of the transmitted and received electromagnetic energy to reduce or minimize clutter and to enhance a target.