On the design of IIR digital filter using linearized equation systems

This paper introduces a novel procedure for the design of IIR digital filters using linearized equation systems. The equations are related to the poles and zeros radii and angles, and are obtained via Taylor Series Expansion. The premise is that the IIR filters satisfy a given set of magnitude response specifications, achieving maximum deviation at determined number of extreme points, related to the number of poles and zeros. The proposed procedure makes it easier the addition of constraints such as maximally flatness, fixed transmission zeros, phase distortion, and most importantly, guarantees filter stability. Efficiency of the technique, robustness and phase distortion are shown through computer simulation results.