Impedance boundary condition simulation in the FDTD/FVTD hybrid

The simulation of the impedance boundary condition (IBC) for the finite-difference time-domain (FDTD) and the finite-volume time domain (FVTD) hybrid algorithm with overlapping grids is explained in detail. This paper does not discuss the validity of the IBC model, and our model assumes the surface impedance or surface admittance has a constant resistive part and a nonnegative imaginary part, which is a linear function of frequency. This model is restrictive. But, with this assumption, the use of a convolution integral is avoided and for many applications this is sufficient. Comparisons of the calculations, based on our time-domain algorithm with the Mie series solutions and the method of moment (MoM) solutions, are given. The agreement between our solutions and the referenced solutions shows that our IBC simulation gives credible numerical results.