Fast waveguide eigenanalysis by wide-band finite-element model-order reduction

An efficient method for fast wide-band eigenmode analysis is presented in this paper. The finite-element solution space is projected to a subspace containing frequency-dependent information obtained at a single frequency by a Lanczos algorithm and modified perturbation theory, resulting in a single-point reduced-order model accurate over an extremely wide frequency range. A numerical procedure is developed to extract a desired mode from the reduced-order model for fast frequency sweep and is then applied to several practical problems, which demonstrate the solution accuracy and computational efficiency of the proposed method.