Finite element analysis of resonant cavities and waveguides using a vector potential formulation

A comprehensive resonant analysis capability is derived from a general formulation of finite element field analysis. By using vector and scalar potential functions as solution variables, the formulation can represent arbitrary geometries containing inhomogeneous, anisotropic dielectrics. All mode types are obtained from a single analysis without spurious mode difficulties. Two types of physical modes are found. Electrostatic modes represent electrostatic behavior at zero frequency, while microwave modes represent high-frequency resonant behavior. Spurious divergence modes are shifted to still higher frequencies (out of the range of interest) in a way that does not affect physical modes. The primary applications are in the computer-aided design of nonuniformly loaded cavities and waveguides.<>