Efficient Integral Equation Method Of The Media, Electromagnetic Scattering Study

The electromagnetic scattering of dielectric bodies has been extensively studied because of its importance in the area of wireless communication and radar. The integral equation is widely applied to analyze the electromagnetic scattering of dielectric objects for its high precision. In this thesis, the research work is based on efficient integral equations for electromagnetic scattering property of dielectric materials. Single integral equation(SIE) and volume integral equation with the solenoidal basis function are investigated. The number of the unknowns is reduced and the iterative solution of the matrix equation is more efficient than the traditional methods. Two efficient methods including adaptive cross approximation (ACA) algorithm and multilevel fast multipole algorithm (MLFMA) are adopted to reduced the storage requirement and computational cost successfully.Firstly, the surface integral equation method for dielectric objects is introduced. Surface integral equations for dielectric objects based on equivalent principle, such as PMCHW, TENENH, JMCFIE are presented in detail. Numerical results show that the programs are correct.Secondly, a novel surface integral equation called single integral equation is presented to realize efficient solution of scattering from dielectric objects. Further, the SIE is extended successfully into the PMCHW,TENENH and JMCFIE. Numerical results by this method are in good agreement with the exact results. And, the convergence speed of the iterative solution of the matrix equation in SIE method is significantly better than that of the traditional coupled integral equations method. Then, the efficient integral method for electromagnetic scattering property of electrically-large object is investigated. Since the memory requirement and computational complexity are both O ( N 2), where N is the number of unknowns. It requires very expensive storage and CPU time when dealing with the electrically-large object. In this thesis, a efficient method called ACA algorithm is adopted to further reduce the storage requirement and computational complexity successfully.Finally, the solenoidal basis function for the volume integral equation is studied. The detailed formulations for implementation, especially the technique for treating singular integration in the method of moment are given. Numerical results show that the proposed approach is valid. The MLFMA algorithm is successfully realized for the volume integral equation solution. It provides an efficient analysis tool for numerical solution of scattering from 3D inhomogeneous dielectric.