Complex Coordinate System as a Generalized Absorbing Boundary Condition

By a change of variables, we show that Maxwell's equations for PML media reduce to ordinary Maxwell's equations but with complex coordinate systems. Many closed form solutions for Maxwell's equations map to corresponding closed form solutions in complex coordinate systems. Numerical simulations with the closed form solutions show that metallic boxes lined with PML media are highly absorptive lending a better insight into the absorptive properties of PML media. More importantly, the complex coordinate system method can be easily generalized to non-Cartesian coordinate systems, providing absorbing boundary conditions in these coordinate systems. 1. Introduction The perfectly matched layer (PML) as a material absorbing boundary condition was first proposed by Berenger [1]. Later, Katz et al [2] extended it to three dimensions, while Chew and Weedon [3] proposed a coordinate stretching viewpoint. An anisotropic media interpretation has also been proposed by Zack et al [4]. Due to its effi..