# frequency transformation bp to lp

Discussion in 'General Electronics Chat' started by franticAAC, Nov 29, 2012.

1. ### franticAAC Thread Starter New Member

Jun 25, 2012
28
1
hi i've to design a bandpass active filter of 6th order PRB type, but i've a problem in the design procedure.
In order to obtain the desired filter i need to convert the bandpass transfer function in a lowpass transfer function.

Given:
$H(s)=K0*\frac{B0 + B1*T(s) + B2*T^2(s) + B3*T^3(s)}{1 + F2*T^2(s) + F3*T^3(s)}$

with: $T(s)=\frac{k}{k+s}$

what are the step formulas in order to obtain the lowpass transfer function H(s)?

2. ### Audioguru New Member

Dec 20, 2007
9,411
896
What is "PRB"?
Please write in full English words without abbreviations.

3. ### franticAAC Thread Starter New Member

Jun 25, 2012
28
1
primary_resonator_block

4. ### Audioguru New Member

Dec 20, 2007
9,411
896
Thank you for telling its name.
Homework?

Oct 18, 2012
3,531
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6. ### franticAAC Thread Starter New Member

Jun 25, 2012
28
1
@tshuck has found the same paper that i'm studying on.
The problem is that in the design procedure i can't obtain the formulas used to risolve the bandpass to lowpass transformation.