On the construction of uniformly stable multivariate interconnect macromodels

The generalization of linear macromodeling methods to the multivariate case is considered. The general objective is the extraction of a SPICE-compatible equivalent circuit, which represents with good accuracy the external port behavior of the structure of interest both as a function of frequency and one or more design variables, such as geometry and material parameters. We review the state of the art, and we suggest a new model representation based on a mixed rational/piecewise linear interpolation scheme, which allows the deployment of a simple procedure for checking the global stability of the model within the parameter range of interest. The theory is applied to a significant test case.