Digital Chebyshev Filter Design

EXPERIMENT 6: Design of Chebyshev IIR Filter

Day six of DSPP practicals. In theory, this topic was our favourite and we were excelling at solving numericals based on it. But the designing of this filter using SCILAB was just a difficult as designing  Butterworth filter.
The aim of this experiment was designing analog and digital Chebyshev Filter .

 In this experiment we designed a digital Chebyshev filter from analog Chebyshev filter using BLT.

The input specifications were given as

(1) Pass band Attenuation (Ap)

 (2) Stop band Attenuation (As )

(3) Pass band Frequency (Fp) in Hz

(4) Stop band Frequency (Fs) in Hz

(5) Sampling Frequency in Hz

In the end we concluded that in both low pass and high pass filters, poles are inside the unit circle and hence they are stable. For low pass filter there is a definite zero at z=-1 while for high pass filter there is a definite zero at z=1. The values of Ap and As as input are approximately same.

The scene of the previous practical session was recreated. Our lab looked less like a lab and more like a brokerage firm's office and we resembled the stockbrokers. Tempers flaring and voices rising, we finally completed the experiment. By the time we exited the lab, a few members of our batch had become rivals.

Program code: CHEBYSHEV