Abstract: A diplexer for communicating signals in two different frequency bands with separate polarizations in each band may, for example, concurrently separate low frequency received signals of orthogonal polarizations from high frequency transmitted signals, also of orthogonal polarizations. To this end a common square waveguide leads to serially disposed, axially displaced, orthogonal mode transitions at which branches are made to closely coupled lowpass filters that communicate with separate ports for low frequency signal bands. A smaller square waveguide coupled to the second of the orthogonal mode transitions communicates with another orthogonal mode transition at which axially displaced branches communicate with other ports for high frequency signal bands.

Abstract: A compact antenna feed system for orthogonally polarized RF signals includes a waveguide feed having orthogonally disposed internal ridges, a pair of wave detectors coupled to the waveguide feed to receive orthogonally oriented RF signals, and an amplifier housed as part of the feed system to amplify received RF signals prior to communication of the signals outside the feed system. The system is readily switchable by remote control to receive RF signals in either orientation and angular alignment to the orientation of the incoming signals is easily accomplished.