Multimode Horn for a Monopulse Subsystem

The design of a multimode feed horn and coupling network of monopulse feed system is summarized. A new combination of higher modes has been given, which will result in a novel structure that is easier to fabricate and more aseismatic. Coupling slots together with the septums are used for the magic-T. The multimode actuator excite the desired high-order modes that is helpful to make trade-off of the antenna patterns difference. Full wave and theoretical analysis of the feed horn are presented, and far-field patterns are computed. Simulations and measurements showed that the gain difference between the sum and difference patterns is less than 0.9dB.