On tuning the group delay of an active RC all-pass resonator

A general expression is presented for the frequency
\omega_0
of the delay maximum of an all-pass resonator composed of an active bandpass resonator and a summing amplifier. This expression is a function of the resonant frequency and pole-
q
. Through an example using the multiple feedback bandpass resonator, a procedure is presented for aligning the delay response of the corresponding allpass circuit without monitoring delay.