改进的特征基函数法分析电磁散射问题

目标电磁散射特性分析具有重要意义，矩量法等数值方法是求解该类问题的重要工具。当待分析目标的电尺寸增大时，矩量法的内存需求和计算量随之快速增加，极大地限制了可求解问题的规模。宏基函数类方法通过在宏域上构造各种宏基函数，减少未知量数目，实现最终矩阵方程规模的缩减，使分析大规模问题变为可能。重点研究该类方法中近期获得较大发展的特征基函数法，结合物理光学法和球谐函数展开-多层快速多极子技术分析电磁散射问题。数值结果验证了改进的特征基函数法的准确性与高效性。

Analysis of electromagnetic scattering by using modified characteristic basis function method

Analysis of electromagnetic scattering from objects is of significant importance in both theoretical researches and practical applications. Traditional algorithms, say the method of moments (MOM), has been widely used in this field during the past decades. However, with the increase of electric size of objects under consideration, a huge requirement of the in-core memory and the complexity of operations are inevitable in MOM. Macro-basis-function-like approaches circumvent the bottlenecks by generating the sets of high-level basis functions defined over macro domains, and give a rise to a considerable reduction in the number of unknowns, i.e. the scale of matrix equations, hence large scale problems become manageable. The characteristic basis function method (CBFM), one of the promising approaches, is under discussion. Modified CBFM, taking advantage of physical optics (PO) and spherical harmonics expansion-multilevel fast multipole method, is utilized to analyze electromagnetic scattering problems, especially with multiple excitations. Several numerical results are given to demonstrate the accuracy and efficiency of the proposed algorithm.