ABSTRACT
If all the zeros lie in the left-hand s-plane, the filter is called
minimum phase.
The poles and zeros can have real values or occur in complex-conjugate pairs of the form,
s
=
a
±
j
b
, where
b
is nonnegative and
-•
<
a
<
•
. Conjugate zeros on the
j
w
axis are found in notch filters. A filter’s frequency response is found by letting
s
=
j
w
in the filter’s transfer function and then finding 20 times the log of the magnitude of the frequency response function vs.