Numerical method for investigating the propagation of surface waves on dissipative guides

A finite-element method is developed to investigate surface waveguides of complicated shapes in the presence of dissipative materials. The complex propagation constants for axially symmetric TM surface-wave modes on a conducting wire and on a lossy dielectric rod are determined. The results are compared with analytical results and in the case of the dielectric rod, the calculation is extended beyond the limits of accuracy of the perturbation method.