IIR digital filters with equiripple stopband transmission

Recently, a simple technique of introducing transmission zeros into a low-pass all-pole filter transfer function to make its stop-band transmission equiripple has been described by Hazra [1]. It is shown that this technique represents a special case of a more general procedure which Provides not only Hazra´s solution, but also additional filters which are advantageous with regard to the required number of multiplications per sample. The results are demonstrated with the aid of an example.