Compact Full Band OMT Based on Dual-Mode Double-Ridge Waveguide

A nonstandard dual mode, double-ridge waveguide is utilized to design a compact orthomode transducer (OMT). The OMT is terminated with a standard circular waveguide common port and two standard isolated rectangular waveguide ports. The proposed structure exploits a one-fold symmetry to eliminate the coupling to the in-band higher order odd modes within the common port. The proposed concept is utilized to design a full K1-band OMT that is essential for space and mobile applications. Furthermore, the performance of the proposed OMT design is verified through a back-to-back measurement showing an excellent agreement between the full-wave simulations and measurements. Nevertheless, the proposed design achieves a measured matching level of 19 dB for the two modes and isolation level between them beyond 30 dB over the entire band.