clear; fi=1;fs=10;Gc2=0.5; wc=2*pi*fi/fs; omegac=tan(wc/2); alpha=(sqrt(1-Gc2)/(sqrt(Gc2)))*omegac; a=(1-alpha)/(1+alpha); b=(1+a)/2; w=0:pi/300:pi; Hw2=(tan(w/2).^2)./(alpha^2+(tan(w/2)).^2); plot(w/pi,Hw2); grid; hold on;