A Subregion Expansion Method for Computational Electromagnetics

This paper presents a new semi-analytical method for computational electromagnetics. Today, the usual electromagnetic field simulation codes are mainly based on the finite element method (FEM). FEM uses the piecewise low order polynomials to approximate different kind of solution functions. The particular nature of a given problem is not considered, which greatly enhances the method´s applicability but depresses the efficiency. In this method, the entire field domain has to be covered with fine mesh, especially in those parts where the field changes sharply, thus requiring a large number of elements (and also unknowns) to calculate the field with sufficient precision. This often makes the codes useless due to the computation cost (CPU time and memory) before some very complex problems. To overcome these limitations, quick and highly efficient techniques are pursued all along. The semi-analytical method is such a direction. The main idea of this scheme is to combine the advantages of both the high efficiency of analytical techniques and the flexibility of numerical methods.