Calculated Based On The Finite Element Method Of Electromagnetic Scattering

The Finite Element Method (FEM) is one of the major numerical methods in computational electromagnetic. Due to its versatility and flexibility, the FEM is capable of modeling complicated structures as well as inhomogeneous materials. The history and actuality of FEM are analyzed and the basic solving steps of the electromagnetic FEM are given at first. Then, the detail progress of 2D FEM is presented, such as the discrete method of 2^nd order isoparametric element and the disperse program using scalar quantity.When solving electromagnetic (EM) scattering problem with FEM, the infinite region exterior to the scatter must be truncated by an artificial boundary. In this paper, we adopt the Perfectly Matched Layer (PML) as an absorbing condition and give the basic principle of it, on the basis of which we provide the conformal PML (CPML) and discuss the character and attenuation parameter of it. Then the complementary CPML (Com-CPML) is given, which will minish the non-physical reflection with a little increase of computing.Due to the revolutionary symmetry of BOR, we use edge-based vector basis functions to expand the transverse field components and node-based scalar basis functions to expand the angular component. In that way, 3D problem can be solved by 2D methods. Because the matrices of FEM equations are always sparse ones, in order to reduce the CPU storage and solving time, we adopt one dimension compressing storage and conjugate gradient methods to deal with them.