IPO+FMM混合方法结合GRI和级联技术计算电大腔体的RCS

Fast Calculate the RCS of Electrically Large Cavity by IPO+FMM Combined with the GRI and Connection Technology

采用快速方法(FMM,RPFMM,FaFFA)加速迭代物理光学法(IPO)的迭代过程,可以快速计算电大腔体的电磁散射特性。采用广义互易积分,用靠近腔体终端的一个S_t面将腔体分成两段,形状简单光滑的腔体前端用IPO结合快速算法处理,而腔体终端单独分析。为了能够处理深腔体和进一步加快计算速度,将腔体前端进一步分成几个子腔体,每一个子腔体独立分析,通过一个级联方法求得腔体前端在S_t面产生的辐射场,最终在S_t面用广义互易积分求得腔体的RCS。数值计算结果表明该方法是准确的,同时能有效地提高计算速度。

The method combined IPO, FMM, RPFMM, FaFFA can rapidly solve the scattering of three-dimensional cavity. In this paper, the Generalized Reciprocity Integral（GRI） method is applied to treat the cavities with termination. The cavity is divide into two different parts by a surface St which is located sufficiently close to the termination, the front section （typically simple and smooth） is analyzed by a hybrid method which IPO combined with FMM, RPFMM and FaFFA, the termination can be analyzed independently. To solve the deep cavities and improve computing speed the front section of cavity is subdivided into several sections, and each of them is analyzed independently using the IPO combined fast computing method from the rest of the cavity. Then a connection scheme is used to get the scattering field radiated by the front section at the surface St . Finally the RCS of the cavity is get by the GRI at surface St. The numerical results show the hybrid method is accurate enough and can improve effectively computing speed