Frequency Response of Chirp Signal -Eye of Sauron(The Lord of the Rings)

%Code:

clc

clear all

close all

Fs=8000;

t = 0:1/Fs:3;

f = 400;

fi =[];

temp=0;

for i=1:length(t)

    fi=[fi temp];

    temp=temp+0.000025*f;

end

y = 2*sin (2 * pi * t.*fi );

N=length(y);

X = fft(y,N);

w = 0:2*pi/N:2*pi-2*pi/N;

w=w-pi;

subplot(2,1,1);

plot(t,y);

subplot(2,1,2);

y=fftshift(X);

plot(w,abs(y));