20. CHEBYSHEV TYPE-1 ANALOG BANDSTOP FILTER

CHEBYSHEV TYPE-1 ANALOG  BANDSTOP FILTER

%Program for the design of Chebyshev Type-1 Bandstop filter

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

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

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

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

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

W1=2*Wp/fs;

W2=2*Ws/fs;

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

Wn=[W1,W2];

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

w=0:.01:pi;

[h,om]=freqs(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 stopband ripple                    30
enter the passband freq                  2000
enter the stopband freq                   2400
enter the sampling freq                   7000