An Accurate Model for Rectangular Trifurcated Horns

An accurate model of the n-furcated horn in general and a trifurcated horn in particular is presented. This type of horn is frequently used as a feed for reflector antennas in communication satellites. It is relatively lightweight and has low sidelobes and cross-polar levels. The horn is divided into four regions-a flared transformer, an enlarged n-furcated guide, long flare partitioned guides, and an n-furcated guide to aperture junction. A modal analysis of the horn is carried out to obtain the aperture modal content, which is used to compute accurately the radiated fields. The measurements and predictions of the amplitude and phase patterns of a trifurcated horn at the 4/6 GHz band show excellent agreement.