25. CHEBYSHEV TYPE-1 LOWPASS DIGITAL FILTER

CHEBYSHEV TYPE-1 LOWPASS DIGITAL FILTER

%Program for the design of Chebyshev Type-1 low pass digital filter

Rp=input('enter the passband ripple');

Rs=input('enter the stopband ripple');

Wp=input('enter the passband frdeq');

Ws=input('enter the stopband freq');

fs=input('enter the sampling freq');

W1=2*Wp/fs;

W2=2*Ws/fs;

[N,Wn]=CHEB1ORD(W1,W2,Rp,Rs);

[b,a]=CHEBY1(N,Rp,Wn);

w=0:.01:pi;

[h,om]=freqz(b,a,w);

m=20*log10(abs(h));

an=angle(h);

subplot(2,1,1);

plot(om/pi,m);

ylabel('gain in dB');

xlabel('(a)  Normalised frequency');

subplot(2,1,2);

plot(om/pi,an);

xlabel(' (b) Normalised frequency');

ylabel('phase in radians');

RESULT

enter the passband ripple        .2

enter the stopband ripple         45

enter the passband frdeq     1300

enter the stopband freq        1500

enter the sampling freq      10000.