Analysis of the junction between smooth and corrugated cylindrical waveguides in mode converters

A method for determining the scattering matrix of the junction between smooth and corrugated cylindrical waveguides is developed. The model is based on expanding the modal fields for the corrugated waveguide into eigenfunctions of the transmission matrix of a waveguide unit cell. This method, used in conjunction with usual techniques for evaluating the scattering matrix of mode converters, is shown to improve the precision of results obtained by rendering uniform the accuracy of the models applied in the calculations. The analysis is now valid for any size of corrugation depth, and the frequency band, of applicability is enlarged accordingly.<
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