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analog filter order for cheby1

Started by mao mu November 11, 2003
Hi
My target filter is a bandpass analog filter. With N=7, cheby1 returns a 14th
B(s), A(s).
But if the target is a LPF or HPF, the results are 7th order B(s),A(s).
Could somebody explain why bandpass filter design using cheby1 doubles the order
on B(s) and A(s)?
Thanks
maomu




Think of bandpass as a hpf and lpf cascaded together
with appropriate cutoff frequencies.

Navan

--- mao mu <> wrote:
> Hi
> My target filter is a bandpass analog filter. With
> N=7, cheby1 returns a 14th B(s), A(s).
> But if the target is a LPF or HPF, the results are
> 7th order B(s),A(s).
> Could somebody explain why bandpass filter design
> using cheby1 doubles the order
> on B(s) and A(s)?
> Thanks
> maomu >
>
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