# Band-pass Chebyshev filter

Discussion in 'Homework Help' started by rockisforkids, May 18, 2009.

1. ### rockisforkids Thread Starter New Member

Jul 19, 2007
3
0
Hello,

I have to determine the transfer function of a band-pass chebychev filter, with n=2 (2nd order), central frequency f0=1kHz, cutoff frequency fc=670Hz, 3dB ripple in the pass-band and 30dB of gain in the central frequency.
It's also said that for a Chebyshev 1st order polinomy, for a ripple of 3dB, D(S)=S+1.

Im using wikipedia (http://en.wikipedia.org/wiki/Chebyshev_filter) and Sedra's book (microelectronics circuits) but I can't find the way to accomplish it. Someone could help?

I know epsilon=1. In order to have a gain of 30dB in the central frequency, and taking in count that there's a ripple of 3dB, I suppose that the attenuation in the stop band (As) has to be 33dB, however I don't know the "ws" (frequency of stop-band edge).

Arghh im confused. This is just to make a low-pass chebyshev filter. Then, the frequency translation to make the band-pass filter I think its easier...