% EE3032 W7D3 Dr. Durant, Winter 2019-'20
% We derived the Fourier Series for a pulse train with voltage A, period
% T0, and on duration tau, with an on period centered about t=0 (thus an
% even signal).

% Parameters - try varying them
A = 1;
T0 = 3;
tau = 1;

% Derived parameters
w0 = 2*pi/T0; % fundamental frequency in radians/s
nMax = T0*10; % scale up with T0 or 1/f0 so that the total frequency domain is unchanged as T0 varies.
n = -nMax:nMax;

% Here is the expression we derived for the FS. Added /pi due to MATLAB implementation of sinc.
x = A*tau/T0*sinc(n*w0*tau/2/pi);
% The FS is real since x(t) is even. The real portions of the FS coefficients
% correspond to cosines, which are the even signal building blocks.
% What would it indicate about x(t) if the FS coefficients were purely imaginary?
% Given that we take x(t) to be real, what constraint would this impose on the 0th FS coefficient?

% Figure:
figure % create a new figure for each run to allow comparing various T0 values, etc.
stem(n*w0,x, 'LineWidth',3),xlabel('Frequency (radians/s)')
title(T0)