O'Reilly logo

Notes on Digital Signal Processing: Practical Recipes for Design, Analysis and Implementation by C. Britton Rorabaugh

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Note 40. Butterworth Filters

Lowpass Butterworth filters are designed to have a magnitude response that is as flat as possible at low frequencies, and that decreases monotonically with increasing frequency, as shown in Figure 40.1. A lowpass Butterworth filter has a transfer function of the form shown in Math Box 40.1. Examination of this transfer function reveals that a Butterworth lowpass filter is an all-pole design that is completely specified by just two parameters—the number of poles, n, and the 3-dB cutoff frequency, ω3dB. The number of poles is usually set to acheive a desired amount of attenuation, ASB, at and above some specified stopband-edge frequency, ωSB. This frequency and the amount of stopband attenuation are not direct specifications ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required