Study Of Some Key Problems Of FETD

The finite-difference time-domain method has fifty years of development sinceproposed by Yee.it has been applied to many practical problems in engineering.However, the error of modeling steps limits the further application of the method in theanalysis of the electromagnetic characteristics of complex structures.In contrast, theFinite Element Method in Time Domain with the freedom of modeling the complexstructure can well simulate the complex geometrical structure, so it can obtain moreaccurate simulation results in the processing of analysis of complex electromagneticproblemsIn this paper, Firstly it explains the general principles of the finite element methodand then it discusses the absorbing boundary conditions of the finite element method intime domain.The discussion of the paper focuses on the Implementation of algorithmand the effect of ABC and PML absorbing boundary condition. Then, according to thecharacteristic that it is necessary for solving matrix in each time step when the finiteelement method in time domain is used. to accelerate the solution of matrix equation,the method of reducing the size of the matrix or changing its form is used here.For thesolution of a matrix equation, the LU decomposition method is compared withConjugate Gradient method and it is concluded that compared to the Conjugategradient algorithm,LU decomposition method needs larger memory but greatly reducesthe calculation time.