PERFECTLY MATCHED LAYER MESH TERMINATIONS FOR NODAL-BASED FINITE-ELEMENT METHODS IN ELECTROMAGNETIC SCATTERING

The perfectly matched layer (PML) concept introduced by Berenger is im plemented for nodal-based finite-element frequency-domain methods. Sta rting from a scalar/vector potential framework, anisotropic media-equi valent gauge conditions are developed for both coupled and uncoupled ( i.e., direct field) scalar/vector field formulations. The resulting di screte system of equations are shown to be identical for both the anis otropic and stretched coordinate viewpoints of PML mesh termination on node-based finite elements, Reaching this equivalency requires that s pecial attention be paid to the basis/weighting functions used within the PML region, specifically, a material dependency is found to be ess ential. The alternative but identical stretched coordinate approach pr ovides the perspective needed to realize a scheme for generalizing the PML to non-Cartesian mesh terminations which are more natural in the finite-element context, Several benchmark problems and associated nume rical results are presented to demonstrate the performance of the PML on node-based finite elements.