Ok thankyou very much I needed this example because I have a doubt. In my book they say that the amplitude of a cebyshev filter oscillates in the pass band but the question is, if the transfer function has just poles how can the module (bode plot) oscillate (see ripple) ?
To oscillate there should be also zeroes!! In the oscillation the poles move the amplitude down of 20dB and the zeroes move it up...what is my mistake?
A Chebyshev type I filter has only poles, one real and a complex pair in case of 3rd order. Your simplified assumption about relation of poles/zeros and magnitude characteristic doesn't aplly to complex pole pairs, I think.
I think, you can't sketch the magnitude without considering the pole quality factor. Below is an example of a second order Cheybyshev, which represents basically one complex pole pair.