An E-B mixed finite element method for axially uniform electromagnetic waveguides

A numerically stable mixed finite element method for axially uniform electromagnetic waveguides is presented. The mathematical formulation is valid from DC up to optical frequencies. The proposed methodology uses the electric field intensity E and magnetic flux density B as state variables and employs face, edge, and node Whitney elements for the spatial discretization. Low-frequency stability is obtained by enforcing the Maxwell divergence laws explicitly, by means of a discrete Helmholtz decomposition. Numerical examples demonstrate the stability and low error of the suggested approach.