Perfectly Matched Layer based modelling of layered media: Overview and perspective

Whereas the Perfectly Matched Layer (PML) was originally conceived to serve as a reflectionless absorbing boundary condition, terminating the infinite simulation domain in finite difference or finite element electromagnetic field solvers, unexpected applications of the PML arose by using it to close down open layered waveguide configurations. As a tribute to our former colleague, Prof. F. Olyslager, in this contribution, the PML-paradigm for layered media is explained and an overview of this paradigm's applications is presented. A novel illustrative example, focussing on the modelling of periodic microstrip structures, is also provided.