A Priori Error Bound for Moment Matching Approximants of Thermal Models

This article focuses on the moment matching methodology for deriving dynamic compact thermal models (DCTMs) of electronic components. For the first time, an a priori error bound is theoretically established both in the time and frequency domains, which is suited to accurately estimate the approximation error introduced by DCTMs in practical electronics applications. By exploiting this result, it is also shown that the near-optimal choice of matching points previously proposed by one of the authors minimizes the error bound here derived, among all the possible choices of matching points. The introduced error bound is verified by applying the moment matching algorithm to a state-of-the-art packaged InGaP/GaAs heterojunction bipolar transistor (HBT) used in output stages of power amplifiers for handset applications.