Title :
Designing IIR filters with a given 3-dB point
Author :
Losada, Ricardo A. ; Pellisier, V.
Author_Institution :
Mathworks, Inc., Natick, MA, USA
fDate :
7/1/2005 12:00:00 AM
Abstract :
Often in infinite impulse response (IIR) filter design, our critical design parameter is the cutoff frequency at which the filter´s power decays to half (-3 dB) the nominal passband value. This article presents techniques that aid in the design of discrete-time Chebyshev and elliptic filters given a 3-dB attenuation frequency point. These techniques place Chebyshev and elliptic filters on the same footing as Butterworth filters, which traditionally have been designed for a given 3-dB point. The result is that it is easy to replace a Butterworth design with either a Chebyshev or an elliptic filter of the same order and obtain a steeper rolloff at the expense of some ripple in the passband and/or stopband of the filter.
Keywords :
Butterworth filters; Chebyshev filters; IIR filters; discrete time filters; elliptic filters; Butterworth filters; IIR filter design; attenuation frequency point; cutoff frequency; discrete-time Chebyshev filter; elliptic filters; filter power; infinite impulse response filter design; nominal passband value; passband; ripple; rolloff; stopband; Algorithm design and analysis; Attenuation; Band pass filters; Chebyshev approximation; Cutoff frequency; Digital signal processing; IIR filters; Low pass filters; Passband; Signal design;
Journal_Title :
Signal Processing Magazine, IEEE
DOI :
10.1109/MSP.2005.1458297