Application of anisotropic PML in mode-matching analysis of open-ended waveguides

The anisotropic perfectly matched layer (PML) is employed in the mode-matching analysis of an open-ended rectangular waveguide radiating into a layered half space. In the analysis, the layered half space is approximated by a large rectangular waveguide coated with anisotropic PMLs along its walls. Closed form expressions of the eigenvalues and the electromagnetic fields for both TE and TM modes in the anisotropic PML-filled rectangular waveguide are first derived and then used in the mode-matching analysis of the resultant waveguide-junction problem. Numerical results for the aperture admittance and reflection coefficient are presented and compared with available data in the literature. Good agreement is achieved.