Impulse response of Sampled version of a 2nd order Butterworth
lowpass filter obtained by the Impulse invariant approximation.
Cuthbert Nyack
The applet below shows the impulse response of a 2nd order Butterworth
filter in red and the impulse response of a
sampled version of the filter in magenta
obtained by using the impulse invariant approximation.
The 2 responses are "identical" for all sampling times. I.e. the impulse
response of a sampled filter obtained via the impulse invariant method
is a sampled version of the analog filter.
Horizontal scale goes from 0 to 5s and with gains = 1, vertical scale
goes from -1 to +1.
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COPYRIGHT © 1999 Cuthbert A. Nyack.