Characterization of a Class of Waveguide Discontinuities using a Modified mode Approach

Abstract —This paper presents a modified TE~n wave approach which is nsed in conjunction with the mode matching method for the field. theory modeling of a class of waveguide discontinuities. In particular, for characterizing wavegnide discontinnities in which resonant effects occnr, this method resolves conflicting results which have heen observed rising the conventional TE,~,t mode matching techniqne, commonly known from the literature, and the generalized analysis based on a linear snperposition of TE~n and TM~z modes. It is fonnd that resnlts from the modified TE~n mode approach are consistent with the general-ized analysis and agree well with measurements on iris filters and corrugated wavegnide polarizers. In comparison with the generalized TE–TM mode analysis, the modified TE~n mode procedure consumes less memory and CPU time and provides improved convergence behav-ior without sacrificing design accuracy. I