Perfectly matched anisotropic layer for the numerical analysis of unbounded eddy-current problems

An extension of the perfectly matched layer (PML) technique in quasi static fields is developed. The new low-frequency PML is based on a fictitious me dium with diagonal tensor anisotropy, On the basis of a theoretical investi gation, the material properties of the anisotropic layer are specified, so that it will be reflectionless for an arbitrary eddy-current field that may exist in free space. Furthermore, the PML is designed in such a way that o utgoing eddy-current fields are sufficiently absorbed, The effectiveness of the low-frequency PML is validated by the implementation of the finite-ele ment solution of a simple two-dimensional eddy current problem as well as a more complicated three-dimensional one.