Research On Electromagnetic Scattering Characteristics Of 3d Structures Based On Time Domain Discontinuity Galerkin Method

In order to solve the complex electromagnetic problems in the time domain,time-domain finite element(TDFEM)and finite-difference time-domain(FDTD)methods have been proposed.For FDTD,it has good performance in solving the rule model,but its performance is not ideal for complex models.For the time-domain finite element method,due to the adaptability of its meshing height,it can be well solved for complex models,but it has the problem of needing to solve large-scale matrices,and it is not easy to parallel when performing time iterations,so this reason can make Numeral Calculations become slowly.Based on the shortcomings of the above methods,the problems faced by the time domain discontinuation Galerkin(DGTD)method to deal with the above two methods are proposed.The DGTD algorithm not only has unique advantages in dealing with complex problems such as large scale and multiscale,but also can not solve large global matrices due to its own characteristics,and can be highly parallel.Based on this feature,the electromagnetic solution time can be reduced.Considering the good electromagnetic applicability of the DGTD method,it will be used in this paper to solve electromagnetic scattering problems.Firstly,the DGTD algorithm is used in this paper to solve the simplest resonator problem.After the resonator problem is completed,the metal ball is used to apply the absorbing boundary(ABC).Finally,the perfect matching layer(PML)is used to truncate.From the previous research on FEM to the study of DGTD,the validity of the DGTD algorithm is verified by the derivation of the DGTD formula and the analysis of three-dimensional numerical examples.The specific content includes the following aspects:1.The DGTD algorithm is used to study the problem of rectangular resonators,and the field diagram of the cavity with time is obtained.The correctness of the method is verified by comparison with the analytical solution.At the same time,the convergence of the method is verified by an encryption grid.2.Based on the cavity calculation,the metal ball is excited by a plane wave,and its outer boundary is cut by ABC,and the scattering characteristics of the metal ball are studied.Calculate the correctness of the result by calculating the RCS of the metal sphere and comparing it with the calculated result of HFSS.3.Replace ABC with PML layer based on ABC cut-off metal ball,verify the advantage of PML by comparing RCS in this case with RCS using only ABC.4.Through more complex models to verify the correctness and universality of the method.