改进的IPO与FEM混合法分析复杂电大腔体电磁散射

对传统的迭代物理光学法(IPO)进行了改进,使之适合于分析具有非完纯导电边界的电磁问题,并与矢量有限元方法(FEM)相结合,对内壁涂敷介质的具有复杂终端结构的电大尺寸腔体的电磁散射特性进行分析.通过Fresnel反射系数,利用IPO方法处理腔体内壁比较平滑的介质涂敷区域,在结构复杂的终端区域,利用FEM进行分析.利用交界面上场强连续条件实现两个区域之间的电磁耦合.通过迭代,计算出腔体内部稳定的电磁场分布,进而获得整个腔体的散射特性.由于在介质涂敷附近区域避免了FEM处理过程,从而可以节省大量计算时间和内存消耗.

Hybrid method of improved IPO with FEM for the analysis of EM scattering by electrically large complex cavities

The traditional iterative physical optics(IPO) algorithm is modified and adapted to EM problems with imperfectly conducting boundaries. The improved IPO is then hybridized with edge-based finite element method (FEM) for the analysis of EM scattering of electrically large dielectric coated cavities loaded with complex terminal. The dielectric coated region on smooth inner surface of the cavity is treated with IPO utilizing Fresnel reflection coefficient. The terminal region with a complex structure is modeled by FEM. The coupling of IPO and FEM region is realized by the continuity condition at the interface of the two regions. By an iteration process, the EM field distribution within the cavity is predicted and then the scattering fields of the whole cavity are obtained. Computation time and memory consumption are efficiently saved utilizing the improved IPO/FEM due to the avoidance of modeling dielectric coated region with memory consuming FEM.