Computer‐aided development and experimental investigation of a double‐ridged orthomode transducer for modern satellite and space communication systems

Abstract

This article presents results of development, optimization, and experimental measurements of electromagnetic characteristics of a wideband orthomode transducer for satellite and space communications. Analyzed design of the transducer is based on a double-ridged waveguide junction, which allows to obtain high level of discrimination of fundamental electromagnetic modes with perpendicular linear polarizations. Numerical modeling of the designed microwave waveguide orthomode transducer was performed by an effective finite elements method in the frequency domain. Optimization of the structure elements allowed to obtain high quality of matching and to improve the isolation between orthogonal polarizations simultaneously. To optimize the electromagnetic performance of the developed orthomode transducer a trust region method, which previously demonstrated its effectiveness for the improvement of electromagnetic characteristics of waveguide polarization converters, was applied. Experimental measurements of all scattering parameters of an antenna feed system, which included a designed orthomode transducer and a corrugated horn, were performed for the verification of simulated results. Results of computer-aided modeling and of measurements are in agreement. Measured good matching and high level of isolation between orthogonal polarizations confirm effective electromagnetic performance of the developed orthomode transducer. Designed wideband waveguide device can be applied in modern microwave antenna systems operating simultaneously at two linear or circular polarizations of electromagnetic waves.