Research On Time-Domain Finite-Integral Algorithm In Anisotropic Medium

In the past fifty years, the finite-difference time-domain(FDTD) method has become a widely used method in electromagnetic analyses and applications. With the application of new electromagnetic materials in engineering, anisotropic media have become an important issue in the application of FDTD. In this thesis, the characteristics and application of anisotropic media are introduced. Based on the method of FDTD, a time-domain finite-integral technology (TDFIT) for anisotropic media is proposed.Firstly,2D-TDFIT of anisotropic media is presented. Anisotropic media is divided into electrical anisotropic medium and magnetic anisotropic medium, detailed research on which is carried out in this paper. The 2D method proposed is effectively verified by the simulation of targets in 2D circumstance, such as microstrip line and phase shifter.Secondly,3D-TDFIT of anisotropic media with dydadic permittivity and permeability is introduced. In the algorithm proposed in this paper, iosotropic media is regarded as a degradation form of anisotropic media. To develop further application of 3D-TDFIT of anisotropic media, conformal technology of anistotropic media is detailed discussed. The conformal algorithm of dydadic permittivity and permeability is deduced in detail. Meanwhile, conformal technology for anisotropic conductive interfaces is presented. In calculation of interfaces of anisotropic targets, the accuracy of the algorithm is improved without loss of efficiency.At last, a new anisotropic 3D TDFIT method based on coordinate transformation is proposed to reduce algorithm complexity. By coordinate transformation, the dyadic tensor of arbitrary anisotropic targets are converted into diagonal tensor in a new coordinate system. The coupling among components with different directions is greatly reduced during the process of iteration. The efficiency of the algorithm is improved significantly.The work of this paper extends the scope of application of TDFIT, which has broad application prospects in the fields of microwave circuit, camouflage coatings and biological electromagnetism.