Practical Aspects of the Design and Fabrication of High-Performance (sub)mm-Wave Dual-Ridged Waveguide Orthomode Transducers, and Application to a 205–280 GHz Design

Dual-ridged waveguide orthomode transducers (OMTs) are a well-proven type of high-performance waveguide components used for the separation of orthogonal linear polarizations, and wideband designs have been recently demonstrated at frequencies as high as 500 GHz. In this article, we investigate the limits of performance in a narrower bandwidth, 205–280 GHz, and the practical aspects of design and fabrication. We demonstrate the flexibility of this type of OMT in terms of input waveguide type, circular or square, and position and orientation of output waveguides. In all cases, split-block fabrication is possible by combining traditional direct machining with wire electrodischarge machining and the appropriate use of shim-waveguide transitions.