ANALYSIS OF GENERAL LOSSY INHOMOGENEOUS AND ANISOTROPIC WAVE-GUIDES BY THE FINITE-ELEMENT METHOD (FEM) USING EDGE ELEMENTS

Several finite element formulations based on edge elements have been d eveloped in recent years, avoiding the appearance of spurious modes in waveguides, However, no formulation of this kind dealing with general lossy inhomogeneous and anisotropic waveguides has been found in the Literature. In this paper, a new finite element scheme for the most ge neral linear waveguides has been derived from vector wave equations vi a a Galerkin procedure. In this formulation, triangular and quadrilate ral edge elements have been used in order to avoid the spurious soluti ons, Furthermore, the final eigensystem involves only very sparse matr ices, thus allowing important savings in time and memory.