A Simplified Method for IIR Filter Design with Quasi-Equiripple Passband and Least-Squares Stopband

Abstract

The modification of the weighted least squares (WLS) method for IIR filter design based on [5] is presented in the paper. The new algorithm allows to obtain quasi-equiripple approximation of the desired frequency response function in the passband and least squares (LS) approximation in the stopband. Even though the proposed method is very simple, it enables to obtain a larger passband-to-stopband ratio (PSR) of energies and a smaller passband ripple of the designed filter magnitude response when compared with the peak-constrained least-squares method.