A multimode pyramidal horn with symmetrical dielectric loading-a high efficiency feed for reflector antennas in satellite communications

A novel multimode pyramidal horn with symmetric dielectric loading on the horn walls is presented. The horn possesses the desirable features of high aperture efficiency (on-axis gain), low sidelobe levels, and low cross polar radiation suitable for applications in satellite communication. In the development of this efficient pyramidal horn, the technique of multimode generation of high order TE/TM/sub 12/ modes by a step discontinuity and a change ill the horn flare angle for equalizing E- and H-plane patterns at reduced sidelobe levels is combined with symmetrical dielectric loading on the horn walls for aperture efficiency enhancement. This pyramidal feed horn can be used for developing an antenna system with monopulse capability for searching and tracking purposes in radar and astronomy applications. Experimental results are presented on a multimode (double-flare) pyramidal horn for operations in the Ku-band.<>