Primary feeds for boresight-jitter compensation of offset-reflector radar antennas

In a recent study conducted by Rudge and Adatia (1975) the concept of a class of 'matched' feeds for offset parabolic reflectors was introduced, in which the primary-feed was designed to match the vector field distributions at the focus of an asymmetric parabolic reflectors system, and thereby compensate for the cross-polarized fields introduced by the reflector. In another study carried out by Rudge and Adatia (1976) it was demonstrated that very substantial suppression of the offset reflector cross-polar field could be achieved by applying the matched-feed technique to the rectangular elements of the monopulse feed. A description is presented of an investigation in which a single element has been designed and experimentally evaluated to provide confirmation of the matched-feed capabilities of the rectangular waveguide radiator.