You're correct, and I apologize. In fact, the example I gave of a
"quarter wave" filter contradicts the statement about the attenuation. I
was thinking of a Butterworth when I wrote it, but as you point out and
as my own example shows, there are many other types for which the
statement is wrong.
I apologize for the error. Thanks for the correction.
Roy Lewallen, W7EL
Peter O. Brackett wrote:
Roy:
[snip]
The last sentence should read:
A lossless lowpass filter has zero attenuation only at DC.
:
:
Roy Lewallen, W7EL
Ummmm... no that statement is only true for one type of approximation
polynomial.
. . .
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