Application of anisotropic absorbers to the analysis of MMIC devices by the finite element method

Anisotropic material characteristics can be exploited to construct absorbers that provide reflectionless interfaces for waves at arbitrary incident angles. Since their computer implementation requires the specification of appropriate material characteristics only, these perfectly matched layers (PMLs) allow for simple but accurate mesh truncation schemes for the finite element method. The present paper extends the concept of PMLs to waveguides of inhomogeneous cross-sections and layered media. We describe the use of generalized PMLs in a software package for (M)MIC devices and demonstrate the benefits of the suggested approach by two numerical examples.