Synthesis of SPICE-compatible broadband electrical models from n-port scattering parameter data

In this paper an efficient technique for the synthesis of broadband electrical models from multiport scattering parameter data (S-parameter) is presented. A curve fitting algorithm is applied to either measured or simulated S-parameters to generate a frequency-dependent transfer-function matrix representation of the system of interest. By means of macromodel synthesis techniques an equivalent circuit network, consisting of standard circuit elements, is derived from the transfer-function matrix representation. The synthesized networks are compatible with SPICE-based circuit simulators, as demonstrated by numerical examples for a two-port and a four-port system. The proposed method is suitable for the analysis of S-parameter based linear sub-networks in a general circuit environment consisting of lumped/distributed elements and nonlinear devices.