New interpolation and smoothing techniques for nonlinear models

Nonlinear models in circuit simulation software often show a bad convergence behavior. In many cases, this behavior results from non-smooth intrinsic equivalent circuit element behavior due to measurement or extraction inaccuracies. In our paper, we present a new method for smoothing and interpolating n-dimensional grids of equivalent circuit elements using an FFT approach. Furthermore, we demonstrate the influence of model smoothness to a harmonic balance simulation.