Predistortion Filter Design

[kadikaram]

Hello,
I try to do the Predistortion LC Low pass chebyshev filter design. While searching regarding this, I found the the thesis.

https://discovery.ucl.ac.uk/id/eprint/10100700/1/Predistortion_technique_and_it.pdf

( Page no: 27 to 43 ) From those derivation ( at page no: 35) , I can't understand some steps.

Step 1: How they find K value?
Step2: How they find

value

I would like to Thanks if someone explain that derivation.

 

[BradtheRad]

0.3759 is close to 0.3679 = the reciprocal of e (well-known mathematical constant 2.71828).

And...
e appears in the formula for capacitor discharge over time (even though it's a formula not usually seen). So perhaps 1/e is somewhere in the math of this filter topology which contains capacitors and inductors.

And it wouldn't be surprising if the text has a few typos.

 

[kadikaram]

Okay. May I know how they find A(lamda)?

 

[BradtheRad]

Seeing the formula contains \[\lambda\] to powers from 1 to 5...
My guess is it has to do with the filter being 5th order, using coefficients calculated to produce Chebyshev behavior.

 

[kadikaram]

Seeing the formula contains λ to powers from 1 to 5...
My guess is it has to do with the filter being 5th order, using coefficients calculated to produce Chebyshev behavior.

is constant value defined by our-self based on Q value of Inductor/Capacitor. Also, they mentioned λ = S-d = S-0.1 (they assume Q=10 and d = 1/Q)
My Actual doubt is how this formula works

to get get A (λ)

.

 

[kadikaram]

Or If you guys have any other notes for predistortion Filter design will be more helpful.