Higher‐order perfectly matched layer for the implicit CNDG‐FDTD algorithm

Abstract

AbstractOn the basis of complex frequency‐shifted perfectly matched layer (CFS‐PML) formulation, an implementation of the higher‐order PML is proposed to terminate unbounded finite‐difference time domain (FDTD) computational domain. By incorporating the Crank‐Nicolson Douglas‐Gunn algorithm and the bilinear transform method, the proposed scheme can not only maintain the unconditional stability of the CN‐FDTD algorithm in terms of reducing computational time but also take advantage of the higher‐order PML in terms of improving absorbing performance. Numerical examples are provided to demonstrate the performance of the proposal in the homogenous free space and half‐space soil vacuum problems, respectively. It is demonstrated that the proposed unconditionally stable higher‐order CFS‐PML can not only efficiently absorb low‐frequency propagation waves, low‐frequency evanescent waves, and late‐time reflections but also overcome Courant‐Friedrich‐Levy limit.