•Butterworth and Chebyshev filters with sharp cutoffs (high order) carry a penalty that is evident from the positions of their poles in the s plane. Bringing the poles closer to the jw axis increases their Q, which degrades the filter's transient response. Overshoot or ringing at the response edges can result.
•The Bessel filter
represents a trade-off in the opposite
direction from the Butterworth. The Bessel's poles
lie on a locus further from the jw axis. Transient response is improved, but at the expense of a less steep cutoff in the stop-band.