Constant group delay in the passband is achieved with a Bessel Filter. The key characteristic is that the poles lie outside the unit circle and the angles of the poles are equally spaced along the jω-axis. This leads to a transfer function with equal coefficients for the constant term and the linear term.''Constant group delay in the passband is achieved by strategic placement of the poles of the transfer function for a filter of any order'' I have for example to generate a coefficient of low pass filter by matlab dsp toolbox. how can I oknow where I place the poles so can I have a constant group delay?isn't the poles are placed according to the cutoff frequency and roll off order?
by Jake Hertz
by Aaron Carman