Finite-Element Modeling of Conductive Multilayer Shields by Artificial Material Single-Layer Method

The artificial material single-layer (AMSL) method, recently proposed to model solid conductive shields in finite-element solvers without using a fine discretization, is here extended to model multilayer shields. First, the admittance matrix of a multilayer shield is analytically derived by the transmission line (TL) theory. Then, considering that the field through conductive shields propagates normally to the shield surface, the TL admittance matrix is equated to that of a 1-D finite element to extract the physical constants of a homogenized artificial material. These constants are adopted to model the multilayer shield region in the finite-element method (FEM) calculations by using only one layer of finite elements in the direction of the field propagation. By the AMSL-FEM, the field propagation through the multilayer shield is accurately modeled taking into account the skin effect and avoiding the fine discretization of the shield.