Coupling matrix synthesis of orthomode transducers

In this paper, the multiport coupling matrix theory is adopted to represent the performance of OMT, such as return loss, isolation, cross-polarization. The initial values of the corresponding coupling matrix are synthesized according to the specified return loss and bandwidth by ignoring the weak cross couplings, and then the whole coupling matrix is optimized to achieve all the specifications including the cross-polarization and isolation. Two examples of single-band and dual-band OMTs are presented to validate our approach.