Design of recursive filters with constant group delay and Chebyshev attenuation

This article presents some new results concerning recursive filters design with approximately linear phase and Chebyshev stopband attenuation. The denominator polynomial D(z) of the transfer function H(z)=N(zJ/D(z) is used to obtain a maximally flat behavior for the delay in the passband, whereas N(t) describes equiripple amplitude in the stopband. The approach under consideration is based on z-domain concepts. At the end, the paper concludes with several detailed examples and graphics showing the efficacy of the proposed technique.