A deterministic approach to the analysis of three-dimensional waveguide configurations by finite elements and mode matching

A scheme combining nodal finite elements and the technique of field expansion into eigenmodes is proposed to determine the equivalent circuit parameters and scattering characteristics of general waveguide junctions. The field description is based on the (A,V)-formulation providing continuous variables for jumps of both permittivity and permeability. To ensure a unique field description the Coulomb gauge is imposed on the magnetic vector potential. Hence, a numerically stable formulation is achieved which was proved to generate no spurious solutions. To verify the reliability of the suggested approach various scattering problems have been investigated. Some numerical results and comparisons are given.>