A novel rational approximation macromodeling algorithm for microwave networks characterized by frequency-sampled data

The problem of computing a rational function approximation to a network function characterized by sampled frequency data is of paramount importance in the modeling and simulation of a variety of microwave and high-speed circuits. In this paper we present a novel method for rational interpolation by the use of bilinear transform of complex frequency variable that solves the numerical difficulties associated with the conventional fitting techniques. Examples are given to demonstrate the robustness and accuracy of the method.