The Cauchy Method

This chapter presents the concept of the Cauchy method for the interpolation and extrapolation of data. The Cauchy method is to interpolate and extrapolate the data from calculating coefficients simultaneously of the numerator and denominator polynomials which are used to approximate the data by a ratio of two polynomials. The usefulness of the Cauchy method is demonstrated for the ease in which it can be incorporated into a Method of Moments program to speed up the computation process over a broad band. The Cauchy method can also be used in the analysis of filters over a broad frequency range. An application of the Cauchy method is in creating a data‐base of many devices working in varying operating conditions. A fast and accurate interpolation algorithm is proposed to reconstruct the high resolution amplitude‐only frequency domain response such as radar cross section and antenna radiation patterns from sparse and non‐uniform samples based on the Cauchy method.