Efficient DSP-Higher-Order PML Formulations for the Metal Plate Buried in Dispersive Soil Half-Space Problem

An efficient and unsplit-field implementation of the higher order perfectly matched layer (PML) based on the stretched coordinate PML (SC-PML) formulations and digital signal processing (DSP) techniques is proposed to truncate the finite-difference time-domain (FDTD) lattices. The higher order PML has the advantages of both the conventional PML and the complex frequency-shifted PML (CFS-PML) in terms of absorbing performances. A 3-D FDTD simulation of the metal plate buried in dispersive soil half-space problem has been carried out to validate these formulations. It is shown that the proposed PML formulations with the higher order scheme are efficient in terms of attenuating both the low-frequency propagating waves and evanescent waves and reducing late-time reflections.