Novel Corrugated Matched Feed for Cross-Polar Cancellation in Tri-Reflector Compact Range

The concept of conjugated field match has been extended to the proposed offset tri-reflector compact range, and a novel tri-slot tri-mode corrugated matched horn has also been developed in this letter. First, the analysis on the field in the focal region of the proposed tri-reflector compact range has been carried out, and a matched aperture field for a multimode corrugated horn is constituted, which shows that the cross-polar component of the CR can be compensated by high-order asymmetrical waveguide mode, such as HE21 mode. Then, a novel tri-slot tri-mode corrugated horn was designed to compensate the cross-polar component of the quiet zone in the proposed CR. Numerical results show that the cross-polar field of the offset tri-reflector CR is compensated by the designed corrugated matched horn successfully. The extended concept of conjugated match and the proposed corrugated horn could be very useful in other offset reflector systems.