A Novel Mode-Transducing Antenna for High-Power Microwave Application

A mode-transducing antenna composed of a coaxial plate-inserted mode converter and a compact coaxial conical horn was presented. The antenna transforms the TEM mode into coaxial TE
₁₁
mode firstly and then radiates it from the coaxial conical horn. It has the virtues of compactness, high aperture efficiency, boresight peak, and low sidelobe level. An antenna for a 1.76 GHz magnetically insulated transmission-line oscillator (MILO) was designed with a length of 60 cm and an aperture radius of 23.5 cm. It produces a gain of 17.4 dBi with an aperture efficiency of 74%. The test results are in good agreement with the simulations. The antenna also presents good performances in the high-power microwave experiments of the MILO