An Implicit 4-Stage ADI Wave-Equation PML Algorithm for 2-D FDTD Simulations

In this letter, an implicit four-stage alternating direction implicit wave-equation perfectly matched layer (4S-ADI-WEPML) algorithm is presented for source-free two-dimensional (2-D) finite-difference time-domain (FDTD) problems. The algorithm is based on splitting each FDTD time step (Delta_t) into four stages with a uniform time increment of Delta_t/4. It has been observed that the proposed algorithm outperforms the classical two-stage ADI-WEPML scheme with a considerable decrease in the computational time and memory storage requirements.