Equivalent circuit extraction from the measured S-parameters of electronic packages

A technique of constructing an equivalent circuit of high-performance electronic packages with the measured s-parameters is presented. First, the robust rational functions for the imaginary and the real parts of the z-parameters transformed from the measured s-parameters are obtained by using the linear rational function approximation. With the rational function expanding into partial fraction, the poles and zeroes of the z-parameters are calculated. And then equivalent circuits of the package are extracted from the poles, the zeroes and the coefficients of the rational functions. In order to verify the equivalent circuits, the s-parameters calculated from the equivalent circuits are compared with the measured ones