Subgridding Boundary Conditions to Model Arbitrarily Dispersive Thin Planar Materials

Abstract

In a previous work, we presented a hybrid implicit–explicit Crank–Nicolson finite-difference time-domain method for treating multilayered lossy thin slabs. The main advantage of this method was its capability to overcome certain late-time stability issues of the conventional surface impedance boundary condition approaches. In this communication, we extend this method to deal with thin slabs having arbitrarily dispersive profiles. This approach is validated with the analysis of a spherical shell made of a metallic wire mesh whose macroscopic equivalent constitutive parameters are derived from its microscopic structure. The results for the electric field inside the sphere are compared against the analytical data and show good agreement with them.