Waveguide feed network producing dual-linear and dual-circular polarizations for satellite applications

A satellite-based waveguide feed network was designed that can produce dual LP in one band and dual CP in another. This design is simpler than the alternative designs, not having a symmetric OMT and requiring fewer phase matched paths. Because phase errors only rotate the linear polarization and do not degrade it, there is no cross-polarization risk due to phase errors for applications where the ground station is free to rotate its polarization to match the satellite polarization. Additionally, the bandwidth of the network is not limited by the axial ratio bandwidth of the septum polarizer, since a good axial ratio is not required in the LP band. Measurements demonstrate cross-polarization isolation levels >;48 dB.