A modified INBC for FDTD analyzing of shielding cavity with thin conductive layers under plane wave incidence

Abstract

A modified impedance network boundary condition (INBC) is proposed for modeling electrically thin conductive layers (TCLs) under plane wave incidence in finite-difference time-domain (FDTD) method. Compared to the conventional INBC which represents the relationship between the electric and the magnetic fields collocated at two faces of the TCL, the modified INBC takes into consideration both the half-space-cell and half-time-step difference of the electric and the magnetic fields in Yee’s grid. The primary advantage of the modified INBC is that it can be implemented in conventional FDTD algorithm without half-cell shift approximation. Numerical examples are presented to validate the efficiency and accuracy of the proposed method in analyzing thin layers with low conductivities.