Design of broadband planar orthomode transducers using substrate integrated waveguide

A broadband planar orthomode transducer has been implemented using substrate integrated waveguide and its design process has been presented. A simple quadruple-ridge transition has been used to achieve a good impedance match between a square waveguide and SIW over a wide frequency range. Compared to the waveguide OMT, the SIW-OMT is very low in profile, easy to fabricate, and can be readily integrated with other planar circuits including the antenna feed.