This was the second experiment using scilab. It was similar to the previous experiment but here we were designing a chebyshev filter.
The Chebyshev filter was designed using the algorithm discussed in class. Input specifications are Pass band frequency,Stop band frequency, Pass band attenuation, Stop band attenuation, Sampling frequency. Filter order is calculated as N for LPF & for HPF. Analog Chebyshev filter design requires computing ε,μ, a,b, Φk, poles, quadrature polynomial, constant and finally denormalized filter H(s) from H^(s).
In chebyshev, the number of ripple peaks represent the order of the filter. Magnitude and pole zero plot was plotted of both LPF and HPF chebyshev filters. The poles were within the unit cirle.
The Chebyshev filter was designed using the algorithm discussed in class. Input specifications are Pass band frequency,Stop band frequency, Pass band attenuation, Stop band attenuation, Sampling frequency. Filter order is calculated as N for LPF & for HPF. Analog Chebyshev filter design requires computing ε,μ, a,b, Φk, poles, quadrature polynomial, constant and finally denormalized filter H(s) from H^(s).
In chebyshev, the number of ripple peaks represent the order of the filter. Magnitude and pole zero plot was plotted of both LPF and HPF chebyshev filters. The poles were within the unit cirle.
The magnitude spectrum is equi-ripple in passband and monotonic in stop band. In butterworth filter, it was observed the opposite. For the same parameters the order of chebyshev filter is less than of butterworth filters.
It was noticed that in the output magnitude response, there is a ripple in the pass band with the total number of valleys and peaks equal to order of the filter.
https://drive.google.com/open?id=0B2dvoOHjY9tfLUF2UVNtSDIyMHM
as we increase N , what is the effect on phase response plot ?
ReplyDeleteChebyshev Filter has a higher roll off than butterworth filter hence the transition band is smaller.
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