To write a MATLAB program to perform the Fourier Transform for continuous time signals

 Source code 1:

clc;

clear all;

close all;

t=-5:.01:5;

x=[zeros(1,300) ones(1,401) zeros(1,300)]; % Generate the input signal – square wave

figure;

plot(t,x);

axis([-5 5 0 2]);

xlabel('time');

ylabel('amplitude');

title('continuous time signal');

k=0;

for f=-5:.01:5

k=k+1;

X(k)=trapz(t,x.*exp(-j*2*pi*f*t)); % Fourier transform of x(t)

end

f=-5:.01:5;

figure;

plot(f,X);

xlabel('frequency');

ylabel('magnitude');

title('Frequency response');

 Source code 2:

clc;

close all;

N=250;

ts=.0002;

t=[0:N-1]*ts;

x=cos(2*pi*100*t)+cos(2*pi*500*t); % Generate the input signal – signal consist of

two frequency components

figure;

plot(t,x)

xlabel('time');

ylabel('amplitude');

title('continuous time signal');

k=0;

for f=0:1:800

k=k+1;

X(k)=trapz(t,x.*exp(-j*2*pi*f*t)); % Fourier transform of x(t)

End

f=0:800;

figure;

plot(f,X);

xlabel('frequency');

ylabel('magnitude');

title('Frequency response');