Study Of Key Techniques Of FDTD And MoM And Applications Of Parallel Computational Electromagnetics

The developing of complicated software on Computational Electromagnetics with parallel techniques and the studying of typical parallelization algorithms are of both technical and strategical significance in increasing the domestic capacity for analyzing EM characteristics for targets in complicated EM environments.For technical computing, MPI has displaced most other message-passing systems. It is a library specification for message-passing, proposed as a standard by a broadly based committee of vendors, implementors, and users. The work concerning parallelizatibn done in this thesis is practically based upon MPI.In this thesis, key techniques and parallelization of several widely used numerical computational electromagnetic methods are studied. Three problems known as typical in engineering are: 1) too much time is needed for analyzing the radiating pattern of airborne antennas; 2) curved boundary structures in slot array can't be easily modeled; 3) complicated EBG structures are difficulty to simulate. These problems are efficiently resolved to some degree in this thesis.Firstly, the parallel UTD algorithm is presented based on the Domain Decomposition Method. Numerical results show that parallel UTD algorithm can drastically reduce the computing time. The parallel UTD method provides a solid foundation for producing complicated EMC software on small computer systems.Then, a modified locally conformal FDTD (MLC-FDTD) scheme suitable for analyzing bulletheaded slots is presented. The MLC-FDTD is also parallelized for analyzing EBG structures. The Parallelized Conformal FDTD is continuously run on a PC cluster for several days to solve a Thousand-Million-Grid FDTD problem. This manifests the efficiency, robustness and accuracy of the Parallel MLC-FDTD. Furthermore, the MLC-FDTD is studied to save computational resources by combining it with a type of non-uniform FDTD scheme, which we refer to as NUMLC-FDTD.Finally, a Basis Function Neighbor (BFN) preconditioning method is presented to solve the equation system obtained from the application of the moment methods. It is a physically based general-purposed preconditioning method for any type of basis function. Numerical results show that the proposed preconditioner can approximately improve the convergence of an iterative solution by several times and in some cases, even an order of magnitude. To enable MoM to analyze electrical large targets, Parallel MoM is studied at the end of the thesis.To sum Up, the systematical study in this thesis of the three widely used computational electromagnetic methods, namely UTD, FDTD, and MoM, are reviewed. The schemes for parallelizing the Hybrid numerical method concerning the three methods are also presented.