The error in the following code:

              F0 =13;
              T0 =1/F0;
              Ts = 0.07;
              t  = 0:Ts:13*T0;
              x = real(exp(j*(2*pi*F0*t-pi/2)));
              plot(t,x)

is the value for Ts is too large. The sampling frequency needs to much smaller to get a good result.

If we change the value to 1/2000 the code will work as expected.

         F0 =13;
         T0 =1/F0;
         Ts = 1/2000;
         t  = 0:Ts:13*T0;
         x = real(exp(j*(2*pi*F0*t-pi/2)));
         plot(t,x)

Alumni Liaison

Correspondence Chess Grandmaster and Purdue Alumni

Prof. Dan Fleetwood