基于FE-BI的介质粗糙面上方涂覆目标电磁散射特性研究

Electromagnetic scattering characteristics of a coated target above a dielectric rough surface based on the FE-BI method

采用有限元-边界积分(finite element boundary integral,FE-BI)方法研究了介质粗糙面上方涂覆目标的复合电磁散射特性,推导了一维介质粗糙面上方二维涂覆目标电磁散射的FE-BI公式.在仿真中,采用功能强大的有限元方法模拟涂覆目标内部场,对于涂覆目标与粗糙面之间的多重耦合作用则通过边界积分方程方法进行考虑.结合Monte-Carlo方法,数值计算了介质高斯粗糙面上方涂覆圆柱目标的电磁散射,分析了涂层材料介电常数、粗糙面粗糙度以及介质粗糙面介电常数变化对复合模型双站散射系数的影响.数值结果表明,相比于传统矩量法(method of moment,MoM),本文方法虽然在处理理想导体模型时效率略低,但可以处理MoM难以处理的复杂媒质电磁散射问题,且计算精度较高.

The composite electromagnetic scattering characteristics of a coated target above a dielectric rough surface are studied by finite element boundary integral(FE-BI)method in this paper.The FE-BI formulation for the electromagnetic scattering from a two-dimensional coated target above a one-dimensional dielectric rough surface is derived.In the simulation,the fields inside the coated target are modelled by powerful finite element method and the multi-interactions between the coated target and the rough surface are taken into account by boundary integral equation method.Combined with the Monte-Carlo method,the scattering from a coated cylinder above a dielectric Gaussian rough surface is numerically calculated and the influence of the relative permittivities of the coating,the roughness of the rough surface and the relative permittivities of the rough surface on the bistatic scattering coefficient of the composite model are analyzed.The numerical results show that,compared with the traditional MoM,the efficiency of our method is slightly lower in dealing with the ideal conductor model.But our method can deal with the complex medium electromagnetic scattering problem which MoM is difficult to deal with,and the calculation accuracy is higher.