Study On The Characteristics Of Electromagnetic Metamaterials Based On Dispersive Finite-Difference Time-Domain Method

In computational electromagnetics,the Finite Difference Time Domain(FDTD)has always been an important numerical method,which has been used in many fields: transient electromagnetic field,radar cross-section(RCS)calculation,microwave components,target electromagnetic scattering,and antenna simulation and design.In 2001,the world's first artificial metamaterial sample was proposed in the United States.Due to its unique electromagnetic characteristics,its dielectric constant and permeability are negative at the same time,which has attracted the attention of many scholars.In recent decades,the interaction between electromagnetic waves and various electromagnetic metamaterials has been a research hotspot.With the progress of science and technology,more and more researchers begin to pay attention to the application of new artificial electromagnetic materials with great potential.In this thesis,the numerical dispersion model of finitedifference time-domain method and its application in electromagnetic metamaterials are studied.By studying the new dispersive FDTD method,the new FDTD method is applied to the simulation of typical new artificial electromagnetic materials,so as to improve the efficiency and precision of the design of new artificial electromagnetic materials.The main contents of the thesis are arranged as follows:1.Firstly,the basic knowledge of FDTD is introduced.The brief overview of the development history of FDTD method are outlined.Then,the basic knowledge of FDTD and different absorption boundary conditions are introduced.2.The three different FDTD methods for dealing with dispersive media are introduced:Piecewise Linear Recursive Convolution(PLRC);Auxiliary Differential Equation(ADE)and Z Transform(ZT)methods.3.The electromagnetic metamaterials were simulated and compared in terms of accuracy,memory requirements and computation time by using the methods with one and two dimensional ADE-FDTD,PLRC-FDTD and ZT-FDTD methods.4.Finally,focusing on ADE-FDTD method,we developed the 3D ADE-FDTD algorithm for numerical simulation of a variety of typical electromagnetic metamaterials.