Package macromodeling via time-domain vector fitting

This paper addresses the construction of lumped macromodels for package structures. A technique named Time-Domain Vector Fitting (TD-VF) is introduced for the identification of the dominant poles of the structure. This method uses as raw data transient excitations and responses at the ports of the structure. These responses are easily obtained from transient full-wave electromagnetic solvers based, e.g., on Finite Differences. The rational approximation can be easily synthesized into a SPICE-compatible subcircuit providing a broadband approximation to the input-output behavior of the package.