Optimization of the Perfectly Matched Layer for the Finite-Element Time-Domain Method

We present a new formulation to implement the complex frequency shifted-perfectly matched layer (CFS-PML) for boundary truncation in 2-D vector finite-element time-domain method directly applied to Maxwell's equations. It is shown that the proposed method is highly absorptive to evanescent modes when computing the wave interaction of elongated structures or sharp corners. The impact of the CFS-PML parameters on the reflection error is investigated and optimal choices of these parameters are derived

I. Introduction

The perfectly matched layer (PML) introduced by Bérenger [1] is widely accepted as an efficient numerical absorber used in time-domain electromagnetic solvers. PMLs are often used to implement absorbing boundary conditions (ABCs) in the finite-difference time-domain (FDTD) [1]–[3] and finite-element frequency-domain (FEFD) [4], [5] methods for simulating open-region wave propagation problems. Recently, a PML scheme to truncate finite-element time-domain (FETD) meshes for analyzing 2-D [6] and generally for 3-D [7], [8] open-region electromagnetic scattering and radiation problems has been developed.