Fast Eigenmodes Analysis for Ridged Rectangular/Circular Waveguides by an Effcient Procedure

We present a new procedure to determine the eigenmodes of a ridged rectangular/circular waveguides. The Galerkin procedure and the BEM are used to solve the numerical problem. This procedure, applied to the planar structures, is based on the use of a monotonous function in the place of the usual determinant to solve non-linear eigenvalue problems. The electric field is expressed using the scalar Green´s function (TM case) and the vector Green´s functions (TE case). In this paper, we use a systematic procedure to solve the final homogenous system. The efficiency of this approach consists in vanishing of a function which results from the building of a quadratic form associated with the operator appearing in the formulation of the problem rather than vanishing the determinant itself. Computing time is short. Results from the present procedure are compared with available data; excellent agreement is documented.