The Study Of Discontinuous Galerkin Method For Electromagnetic Scattering From Heterogeneous Media

The application of complex medium is playing an increasingly important role in modern military and civil fields.Especially with the rapid development of communication tech-nology today,target stealth and anti-stealth technology become the key factors to deter-mine the victory or defeat of war.Due to the complexity of electromagnetic environment in modern battlefield,the medium develops from simple metal to mixed and metal coated media.Therefore,accurate and effective analysis of electromagnetic scattering of complex media has important application value.Based on Volume Integral Equation(VIE),this pa-per focuses on the application of Discontinuous Galerkin method(DG)in electromagnetic scattering of complex media.We study the application of Piecewise Contant Vector(PCV)and SWG(Schaubert-Wilton-Glisson)basis functions in Discontinuous Galerkin method,re-spectively.This paper analyzes the shape,dimension and condition of the impedance matrix and their influence on the calculation efficiency,and proposes a method of using SWG basis function to directly expand the electric field intensity E,which can effectively improve the behavior of the impedance matrix.Numerical examples are given to verify the correctness and effectiveness of the proposed method.The main contents of this paper are as follows:Firstly,the modeling method of electromagnetic target is studied.According to the geomet-ric characteristics and media composition of the calculated target,the geometric model of the target was established by using Rhinoceros software,and then the electromagnetic model of the target was established by using the non-conformal and non-matching tetrahedral mesh discrete target according to the characteristics of the target's electromagnetic parameters,thus providing the model parameters for realizing the Discontinuous Galerkin method.Then,this paper studies the basic ideas of the Discontinuous Galerkin method,principle and realization method,the paper used the Piecewise Constant Vector basis functions,it defined on a tetrahedron,it's unnecessary to consider if there is a public face,the boundary between tetrahedron,it's form is simple,easy to calculate,especially the singular integral equation is easy to handle,the paper gives a detailed derivation and calculation formula,a numerical example shows that based on Piecewise Constant Vector basis functions of Discontinuous Galerkin method and the traditional basis function of calculation accuracy,However,it can greatly reduce the difficulty of modeling and mesh subdivision.In order to further improve the efficiency of the Discontinuous Galerkin method,the paper also introduces the SWG basis function in discontinuous galerkin method,it can use less number of elements,on the premise of keeping basic equal precision,using the SWG basis function can reduce the number of elements required,however,produced by the method of impedance matrix is morbid,difficult to solve.To solve this problem,this paper proposes the idea of directly using SWG basis function to expand the electric field intensity E,so as to effectively improve the behavior of impedance matrix and improve the convergence speed of solving impedance matrix.