I wrote a amplitude modulation block and here’s an interesting problem:
It seemed that the Freq showed on the plot of post modulation FFT is
always (1/80) of the freq I set in the SW. For example, If I set the
sub-carrier freq to 2MHz, and use a message signal (constant 1.0)to
modulate that, I can only get a 50KHz sub-carrier showed on FFT plot.
I’ve attached my plots(both in freq and time domain).
Below are the test results:
freq. in post-mod FFT freq. set in SW
Is there anyone who has some ideas or comments? Thank you!