Efficient Z-Transform Implementation of the D-B CFS-PML for Truncating Multi-Term Dispersive FDTD Domains

Efficient Z-transform implementation of the Complex Frequency-Shifted Perfectly Matched Layer (CFS-PML) using the D-B formulations are proposed to truncate open region multi-term dispersive Finite-Difference Time-Domain (FDTD) lattices. These formulations are independent of material properties of the FDTD domains and hence can be used for modeling general media because of the D-B constitutive relations. A Three-Dimensional (3-D) simulation of the two-term Lorentz dispersive FDTD domain has been carried out to demonstrate the validity of the proposed formulations. Furthermore, in order to show the validity of the proposed algorithm, the second 3D inhomogeneous problem has also been used for validating the proposed formulations. It is clearly shown that the new formulations with the CFS-PML scheme are efficient in attenuating evanescent waves and reducing late-time reflections.