Macro-elements for efficient FEM simulation of small geometric features in waveguide components

This paper introduces a novel class of specially-constructed elements aimed at the expedient finite-element modeling of waveguide components containing fine geometric/material features such as dielectric and conducting posts. Instead of utilizing a very fine grid to resolve such fine features, special elements are constructed, of the size of the regular grid, that capture accurately the electro-magnetic properties of the fine features. Use of the proposed macro-elements leads to significant reduction in the number of unknowns in the finite-element approximation of the structure without sacrificing solution accuracy.