A K/Ka band Planar Dual-polarization Waveguide Diplexer

In this paper, a dual-band planar diplexer is proposed for K/Ka band satellite communications. A rotational planar topology structure is designed to minimize the system profile to only one layer. An externally convex quad-ridged waveguide is applied to the classic orthomode junction (OMJ) to improve its broadband performance. The results show that the -20 dB bandwidth(17.1GHz - 21.2GHz/27.3GHz - 31.3GHz) of the proposed OMJ covers the whole satellite communications bandwidth in K/Ka band. Its broadband performance and simpler manufacturing process indicates great potential in the application of millimeter wave and satellite communications.