Multimode horn antennas with square aperture loading grooves for circular beam and low cross-polarization characteristic

摘要

This paper proposes a horn antenna with a square aperture radiating a circular beam. The horn has a structure which loaded 90° rotationally symmetric grooves for shortening the axial length. Dimensions are determined by optimization so that optimum mode coefficients calculated by the quadratic programming are obtained on the horn aperture. Effectiveness of the designed horn is verified numerically and experimentally.