Design of A Multimode Corrugated Horn for Single Offset Reflector Antenna

摘要

In this paper, a multimode corrugated horn for single offset parabolic reflector antennas is proposed, which is conjugate matched and significantly reduces the cross polarization level in secondary radiation pattern of an offset parabolic reflector antenna system with relatively low F/D. This horn introduces higher order mode TE₂₁ with proper amplitude and phase in addition to fundamental TE₁₁ mode by inserting three asymmetrical semi-cylinders. In the corrugate section, six axial corrugation of varying depth is used to convert TE₁₁ and TE₂₁ mode to HE₁₁ and HE₂₁ mode effectively. Inserting three semi cylindrical spectrums makes the cross polarization level drops below -31dB in the working band 14-14.5GHz. And it is easy to process because of its simple and reliable structure.