Advancements in the identification of passive RC networks for compact modeling of thermal effects in electronic devices and systems

We deal with the problem of identifying the parameters of an equivalent lumped RC multiport network from time domain tabulated data of a corresponding distributed real eigenvalues problem, as obtained from either measurements or accurate simulation tools. A novel step response matrix identification procedure is proposed, based on the combination of an outer nonlinear least squares iteration for the relocation of time constants, and an inner convex programming cycle for the identification of the corresponding residue matrix terms, able to guarantee a priori the passivity property of the equivalent RC network. The structure of the algorithm and its principal functions connections are shown, and the mathematical features of the proposed formulation of the identification problem are accurately described and commented. Moreover, the possibility of getting direct synthesis of a Foster generalized concretely passive multiport, as a consequence of the optimal identification of a passive real eigenvalues model from data, is discussed. Since the technique is well suited (although not limited) to the reduced analysis of typical electro-thermal problems, a set of significant case studies in this area is considered. In this way the algorithm present implementation is validated, also comparing it to previous well assessed methods, evidencing its large potential and value.