A dielectric rod antenna as a high efficiency feed for reflector antennas

Radiation characteristics of a short dielectric rod antenna excited by a circular waveguide is investigated experimentally. It is found that, by a proper selection of the waveguide radius and the exposed length of dielectric rod, the E and H plane radiation patterns, the side and back radiations and the bandwidth of the antenna can be controlled. Some experimental data are presented and the usefulness of this antenna as a feed for paraboloidal reflectors is also discussed.