Study On The Meshless Method For Analyzing Electromagnetic Scattering

The traditional numerical method for the problems of electromagnetic scattering (EM) is based on the mesh scheme, both all nodes and facets are needed for the solver. With the more elaborate mesh scheme and more unknown are needed, the solver is often slow and even workless. So in this dissertation, a meshless method (MLM) in terms of the method of fundamental solutions (MFS) is extended to study effectively and accurately for the problems of electromagnetic scattering and radiation, to break the bottleneck of mesh scheme.The basic theory of MFS is discussed firstly in this thesis, and the comparability with conventional integral equation methods is also given. The algorithm mentioned here is based on the fundamental solutions of the wave equation, and the linear combination of these solutions can be used to describe the EM fields needed. For the two-dimensional EM scattering problems, the fields to be solved for can be expressed directly in terms of fundamental solutions of appropriate wave equations, through enforcing the boundary conditions at the collocated points, a matrix equation is founded, after the unknown coefficients is obtained, the problem is settled down. In this section, we study the EM scattering from the metal objects and the dielectric objects, as well as the metal objects coated with dielectric materials, then the errors of results is analyzed particularly. For three-dimensional problems, the pairs of current elements which are perpendicular to each other and tangential to the auxiliary surface are required to describe the vector field functions completely. With the understanding, the EM scattering characteristics from the metal/dielectric bodies are studied in detail, the auxiliary parameters which influence the precision of the results, and the efficiency of MFS in the presence of, are discussed carefully. Finally, the MFS is applied to study electromagnetic scattering from the random rough surfaces, as well as the target above rough surface. A useful approach using MLM in EM scattering is constructed.