Equivalent Circuit Models for Coupling Effects Characterized by Scattering Parameter Data

This paper describes a practical approach for incorporating coupling effects characterized by n-port scattering parameter data into commercial circuit simulators. Using measured or simulated scattering parameter data, passive broadband electrical models of minimal order are synthesized. A robust curve-fitting algorithm and a macromodel synthesis technique are applied to generate an equivalent lumped network con-sisting of standard circuit elements. 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 analyzing coupling effects in a general circuit environment consisting of lumped/distributed elements and nonlinear devices.