Allpass Transfer Function A Simple application a simple but often used application of an allpass filter is as a delay equalizer Let g(z be the transfer function of a digital filter designed to meet a prescribed magnitude response The nonlinear phase response of g()can be corrected by cascading it with an allpass filter A(z)so that the overall cascade has a constant group delay in the band of interest Copyright C 2001, S K Mitra19 Copyright © 2001, S. K. Mitra Allpass Transfer Function A Simple Application • A simple but often used application of an allpass filter is as a delay equalizer • Let G(z) be the transfer function of a digital filter designed to meet a prescribed magnitude response • The nonlinear phase response of G(z) can be corrected by cascading it with an allpass filter A(z) so that the overall cascade has a constant group delay in the band of interest