Shielding Analysis of Uniaxial Anisotropic Multilayer Structure by Impedance Network Boundary Condition Method

This paper presents a modeling approach for analyzing the shielding properties of uniaxial anisotropic thin conductive layer (TCL) by impedance network boundary condition (INBC) in the finite-difference time-domain method. Based on anisotropic electromagnetic wave propagation theory, the relationship between the tangential electric and magnetic fields is deduced and then modeled by vector fitting method. After that, the multilayer structure composed of anisotropic TCLs is represented as a cascaded network. With the coordinate transformation technology, the optical axis of the medium can be at any angle. Two additional cascaded air layers are adopted to avoid the “H-node shift” approximation, and the exponential time difference scheme is introduced to improve the calculation accuracy in applying INBC models. Three numerical examples are used to validate the efficiency of the proposed method in analyzing shielding properties of single/multilayer panels and cavity structure.