Analysis of Cylindrical Waveguides of General Cross-Section

This paper describes a novel method for the analysis of waveguides of general cross-section. In this approach the field inside the waveguide is expanded in terms of cylindrical wave functions. The field is then subjected to the pertinent boundary conditions via an integral formulation. This procedure leads to a homogeneous system of linear equations from which both the cut-off frequencies and the field distributions of the fundamental and higher-order modes can be computed. The method described is applicable to waveguide cross-sections whose boundary contour functions in terms of a polar representation are single or multi-valued; its extension to doubly-connected cross-sections is possible. Some numerical results are given which demonstrate the good convergence and high accuracy of the approach.