Arbitrarily oriented perfectly matched layer in the frequency domain

An arbitrarily oriented perfectly matched layer (PML) is introduced by using complex space mapping for more flexible meshing of microwave engineering problems. The PML can be oriented in any direction. The discussion is extended to two-direction PMLs for matching the interface between one-direction PMLs, and three-direction PMLs for two-direction ones. An example having analytical solution is calculated, Numerical results agree with the analytical solution very well within 0.1%.