The 2nd-order low-pass Chebyshev filter is well-documented. LPFilter2021.pdf calls it a bump filter, and presents design equations, believed to be unique. No polynomials, just a short series of cookbook equations. Derivations and examples are included. Two follow-up documents are now available.
LP2Flter.pdf describes how to design 2-stage filter, one bump and the other flat.
LPBumpFilterKRC.pdf describes a Sallen-Key circuit that uses equal capacitors while generating a "bump" by adding dc gain.
The two links (copy and paste):
https://drive.google.com/file/d/16H4HlSgQvKtOcMl5k2_I2Oks25cx0Guu/view?usp=sharing
https://drive.google.com/file/d/16RLt8BUZhxpy4x3BcCmQ8yKdCD_NKfO8/view?usp=sharing
Click the button below to get the primary document:
