Numerical computation of guided electromagnetic waves

A computational procedure is presented for the determination of the propagating modes of cylindrical electromagnetic waveguides. The geometrical cross-section of the waveguide is completely arbitrary and may be filled with any homogeneous isotropic material, either dielectric or magnetic or both. A modal decomposition is employed thus reducing the problem to uncoupled Helmholtz equations for transverse electric (TE) and transverse magnetic (TM) modes. The discretization of these two-dimensional Helmholtz equations is accomplished by application of the Control Region Approximation. This is a generalized finite-difference procedure involving the tessellation of the cross-section by dual Dirichlet and Delaunay regions. The discrete propagation constants and modes are determined by an inverse power iteration. Power flow, wall loss, and dielectric loss are then calculated. Numerical results indicating the efficacy of this approach are represented