Waveguide mode solution using a hybrid edge element approach

A hybrid edge element approach for the computation of waveguide modes is presented. The electric field is decomposed into its transverse and longitudinal components, which are modeled in terms of two‐dimensional edge elements and scalar nodal elements, respectively, thereby satisfying the Dirichlet boundary condition at the perfect electric conductor boundaries and dielectric interfaces. Failure to do so results in the generation of spurious modes. This approach allows for the modeling of a three‐dimensional field quantity over a two‐dimensional boundary, namely the waveguide cross section. Another approach, the method of moments, serves as an excellent means of verifying the results obtained through use of hybrid edge elements. A comparison of the results obtained from both techniques are presented, along with the associated field plots obtained from the hybrid edge element approach for several geometries.