%Rectangular signal
A=1;T=1;tau=0.2;
alpha=tau/T;
num=fix(1/alpha); %number by the first zero of envelope
n=-3*num:3*num; %number of components for plotting
Cn=A*alpha*(sinc(n*alpha));
subplot(2,1,1)
stem(n*2*pi/T,abs(Cn));
title('Amplitude spectre');
xlabel('Angular frequency[rad/s]');
ylabel('|Cn|');
grid
subplot(2,1,2)
y=sign(n);
p=angle(Cn+eps);
stem(n*2*pi/T,(y.*p),'r');
title('Phase spectre');
xlabel('Angular frequency[rad/s]');
grid
k=-num:num; % first spectre arcade
Ck=A*alpha*(sinc(k*alpha));
s=sum(abs(Ck).^2); %power evaluated by Parselav's theorem
eta=s/(A*A*alpha) % coefficient of power efficiency of the first spectre arcade
% Triangular signal
figure
subplot(2,1,1);
Cn1=A*alpha*((sinc(n*alpha)).^2);
stem(n*2*pi/T,T*abs(Cn1),'linewidth',2);
title('Amplitude spectre');
xlabel('Angular frequency[rad/s]');
ylabel('|Cn|');
grid
subplot(2,1,2)
y=sign(n);
p=angle(Cn1+eps);
stem(n*2*pi/T,(y.*p),'r','linewidth',2);
title('Phase spectre');
xlabel('Angular frequency[rad/s]');
grid
k1=-num:num;
Ck1=A*alpha*((sinc(k1*alpha)).^2);
s1=sum(Ck1.^2); %power