Study Of FDTD Algorithm Of Electromagnetic Scattering By Complex Media And Related Techniques

Based on the Yee's cell theory, averaging value method and interpolation method, the FDTD method for electromagnetic scattering by anisotropic media is presented. By analyzing the anisotropic media FDTD iterative formulas, the computation of each electric or magnetic field component node involves the 28 nodes around it.On the basis of the serial FDTD for anisotropic media, the parallel FDTD algorithm for media of electric anisotropy and electric-and-magnetic anisotropy are investigated, respectively. To perform the parallel computation, a spatial decomposition, i.e. the FDTD computation space divided into several sub-domains is first carried out. Then a designated individual processor computes the field nodes inside each sub-domain with a small amount of data being communicated from neighboring sub-domains. According to the characteristic of the anisotropic media FDTD computation formulas, there exists an overlapping region between adjacent sub-domains, within which the data communication is needed. In this paper, the data communication rules between adjacent sub-domains are also analyzed for the anisotropic media parallel FDTD in detail.A parallel algorithm for the anisotropic media FDTD method on a distributed network by using the message-passing module is discussed as well. The parallel platform of PVM system is applied to perform FDTD parallel algorithm. The structure of the parallel program adopts a master-slave organization. The functions of the master program mainly include the creation of process, the initialization of iterative, the collection and display of the computation results, and so on. Similarly, the functions of the slave program mainly include the execution of FDTD computation, and the load of slave process is distributed by master process. Finally, flow chat of the parallel FDTD program is given, and the concrete functions of each module are discussed in detail.In these parallel FDTD algorithms for anisotropic media, the special treatment for the absorbing boundary, total-field scattered-field boundary and near-to-far field extrapolation boundary are analyzed in detail. To exemplify the availability of the parallel FDTD algorithm, the electromagnetic scattering of the typical objects are computed. The simulation results of parallel speedup, parallel efficiency is presented in this paper. Then, the relationship of parallel FDTD computation performance with granularity and data commutation is also analyzed.Based on the uniaxial anisotropy perfectly matched layer (UPML) theory, the application of the UPML absorbing boundary in the parallel FDTD algorithm is...