Application of the finite-element method for solving a spectral problem in a waveguide with piecewise constant bi-isotropic filling

Abstract

A spectral problem in a bi-isotropic waveguide filled nonuniformly in the cross section is considered. A generalized formulation of the problem is considered, making possible, while using Lagrange finite elements, a substantial reduction in the number of spurious modes in the spectral region of interest and shifting them to the higher frequency region. An algorithm for calculating the propagation constants and fields in the given waveguide is implemented. A series of calculations of dispersion curves and fields in a waveguide with different cross-section structures are performed.