Dual-polarized fan-beam feed horn

A simple dual-polarized feed horn that radiates fan-shaped primary patterns is described. The radiated patterns for the two orthogonal polarizations are essentially identical and are suitable for illuminating cut paraboloidal reflectors with
f/D
ratios of about 0.3. The horn is similar to conventional flared waveguide feed horns except that the corners have been modified to yield an octagonally shaped aperture. The horn has the added advantage of suppressed
E
-plane sidelobes, thus reducing spillover radiation.