US Patent 7408427 Compact multi-frequency feed with/without tracking

A method and apparatus forming an efficient and compact waveguide feed with all components for processing signals in multi-frequency band antenna feeds with single/dual linear/circular polarizations with/without tracking. The layout can be realized in a split block configuration using any number of fabrication methods, such as brazing, electroforming, and machining and is most effective when it is realized in a split-block construction, in which the waveguide components are formed in the recesses split about the zero current line. This layout results in a very compact feed, which has excellent electrical characteristics, is mechanically robust, eliminates flange connections between components, and is very cost effective.