Closed form design of nearly equiripple low-pass FIR filters

Abstract

A closed form design of nearly equiripple low-pass finite impulse response filters is introduced. The approximation is based on the generating polynomial, which is related to the iso-extremal polynomials. Formulas for the evaluation of the impulse response of the filter has been developed. The practical design procedure based on this approximation is presented. One example is included.