In this experiment we had to design a digital filter from analog filter and study the aliasing effect due to sampling in Impulse Invariant Method and the frequency warping effect in BLT method .
So after obtaining the results i learnt that since observed values and i/p values are not matching , order of the filter had to be increased . The magnitude spectrum is monotonic in stopband and also monotonic in the passband for Digital Butterworth Filter. Analog LPF poles lie on the LHS of the s- plane and digial LPF poles lie inside the unit circle . Hence both analog and digital butterworth LPF are stable .
link for the code : https://drive.google.com/drive/folders/0BwYB93kRygZnT1E1MUNaZXh4RGM
Analog Butterworth LPF has only poles and no zeros.
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ReplyDeleteif an higher order filter is considered then the number of samples increase and thus the resolution of the spectrum increases and the magnitude response looks better .
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