On the eigen-decomposition of electromagnetic systems and the frequency dependence of the associated eigenvalues

The asymptotic waveform evaluation (AWE) technique is a useful way to minimize repeated electromagnetic system computations for multiple frequencies, dramatically reducing wideband solution times. In the context of AWE, it has already been shown (Y.E. Erdemli et al., 1999) (J. Gong and J.L. Volakis, 1996) that use of the Fade rational function for the modeling of unknowns is a superior choice to the Taylor series expansion, providing a wider bandwidth coverage; owing to its enhanced ability to model pole behavior. This paper discusses a close analog to the Fade rational function developed from the eigenvalues of a given electromagnetic system. For Illustrative purposes, we chose the finite element boundary integral (FE-BI) method to demonstrate the application and utility of AWE expansions based on the eigenvalues of the FE-BI matrix system