An effective method combined with finite element method (FEM) and boundary integral method (BIM) is presented in this paper to study the composite electromagnetic scattering from a 2-D coated object partially buried in a 1-D dielectric rough surface. The field within the coated object is modelled by FEM, while the coupling field between the object and rough surface is considered by BIM. The fields inside and outside the object are coupled together via boundary conditions on the boundary of the object. Since the boundary of the object is divided by the rough surface into two parts with different electromagnetic properties, the boundary conditions on the object are more complicated. A detailed derivation of the FEM-BIM formula for the composite model is given in this paper. Our numerical code is validated by the method of moments (MoM), and several numerical simulations are conducted to discuss the scattering characteristics.

提出了一种结合有限元法和边界积分法结合边界元法的有效方法，研究了部分埋入一维电介质粗糙表面的二维涂层物体的复合电磁散射。涂层物体内部的场由FEM建模，而物体与粗糙表面之间的耦合场则由BIM考虑。对象内部和外部的场通过对象边界上的边界条件耦合在一起。由于物体的边界被粗糙表面分成具有不同电磁特性的两部分，因此物体的边界条件更加复杂。本文给出了用于复合模型的FEM-BIM公式的详细推导。我们的数字代码通过矩量法（MoM）进行了验证，