close all

alpha=.99;
f1=2500;
f0=8000;

b=1-alpha;
a=[1 -2*alpha*cos(2*pi*f1/f0) alpha^2];


b1=conv([1 -alpha*cos(2*pi*f1/f0)],b);
b2=conv([0 alpha*sin(2*pi*f1/f0)],b);

figure
plotZTP(b1,a,200,8000)

figure
plotZTP(b2,a,200,8000)