6/13/2005
Filter Approximation Theory
9
•
F(
w
) = T
n
(
w
)
so
–
T
1
(
w
) =
w
and T
n
(
w
) = 2
w
T
n
(
w
) – T
n-1
(
w
)
•
Characteristics
–
Controlled equiripple in the pass-band
–
Sharper cutoff than Butterworth
–
Non-linear phase (Group delay distortion)
L
Chebyshev – Type 1
1
w
|H(
w
)|
2