Conformal PML-FDTD schemes for electromagnetic field simulations: A dynamic stability study

We present a study on the dynamic stability of the perfectly matched layer (PML) absorbing boundary condition for finite-difference time-domain (FDTD) simulations of electromagnetic radiation and scattering problems in body-c onformal orthogonal grids. This work extends a previous dynamic stability a nalysis of Cartesian, cylindrical and spherical PMLs to the case of a confo rmal PML. It is shown that the conformal PML defined over surface terminati ons with positive local radii of curvature (concave surfaces as viewed from inside the computational domain) is dynamically stable, while the conforma l PML defined over surface terminations with a negative local radius (conve x surfaces as viewed from inside the computational domain) is dynamically u nstable. Numerical results illustrate the analysis.