Analysis of the Discontinuity Between Ridged and Rectangular Waveguide by an Efficient Mode-Matching Technique

A modified mode-matching technique is proposed to analyze the transition between a rectangular and a ridged waveguide (with multiple ridges). The techique integrates in an efficient way the computation of TE/TM modes in the ridged waveguide -- found solving a linear eigenvalue problem instead of searching the zeros of a nonlinear equation -- and the evaluation of coupling coefficients -- expressed as one-dimensional instead of two-dimensional integrals of eigenfunction crossproducts.