Radiation characteristics of shaped conical horns

A simple modification to the aperture shape of a conventional conical horn is proposed in order to suppress the high E-plane sidelobe levels over a broad frequency bandwidth. It consists of incorporating a step in the E-plane of a conical horn with plane conducting walls and adjusting the step height for controlling the sidelobe levels. The principal plane radiation patterns of the shaped conical horn are analyzed by the GTD method and show satisfactory agreement when compared with the experimental patterns.