Infinite impulse response filter 2nd,3rd order high pass
The sampled "equivalent" of a second and third order Butterworth high pass filter derived by
use of the bilinear approximation is shown in the applets below. The
Butterworth filter has an lower 3dB frequency of 1rad/s.
First applet shows a second order filter and the second shows a
third order filter.
In applet below vertical scale is from 0 to 4/3 for amplitude,
-pi to pi/3 for phase and horizontal scale is
from 0 to 4rad/s.
In both applets red shows the sampled filter
response, orange shows the analog filter
response, green shows the sampled filter phase
and cyan shows the analog filter phase.
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COPYRIGHT © 1999 Cuthbert A. Nyack.