Broadband Ortho-Mode Transducer for high performance modular feed systems

A high performance broadband Ortho-Mode Transducer (OMT) design with more than 70% bandwidth is based on a novel branching concept with a two-fold symmetric structure. A symmetrical pair of ridge waveguides is facing the common branching region serving one polarization. The orthogonal polarization is coupled by a symmetrical pair of probes associated with coaxial interconnections. Folded Magic Tees are implemented for the re-combination of the semi signal portions of the ridge waveguides and the coaxial interconnections, respectively, to serve the complete signal at the dedicated interface ports. (To overcome the bandwidth limitation of rectangular waveguide solutions, tailored ridge waveguides have been established for the interfacing and internal waveguide interconnections.) This broadband OMT is foreseen as the key building block in a modular feed system approach employed for high capacity data transmission with large radio antennae. The measured characteristics validate the design concept with the required high performance properties that are necessary for these outstanding applications.