Compact dielectric feeds for prime focus reflector antennas

It is argued that small-diameter circular waveguides partially filled with dielectric can be used as compact and efficient feeds for prime focus reflector antennas. Both singlemode and multimode designs are briefly reviewed and evaluated. Results are given for a case where the HE/sub 11/ mode and EH/sub 11/ mode propagate in the dielectric and where the diameter and permittivity have been chosen so that the cross-polar power is minimized.<>