MATLAB: Amplitude Modulation using simulink

amplitudesimulinksine

I am currently doing amplitude modulation using three very high frequency sine waves which I getting perfectly after adding all the three due to already set parameters in the simulation parameter box.
The carrier frequency is also very high, up to 3000 Hz, but the scope is displaying is correctly. But after the message signal and carrier are passing through the product, I am not getting amplitude modulated signal. Instead, I am getting a completely zero straight line. My sample time in the Product is 0.0001.
I am pretty sure it has to do something with the product parameters or simulation parameters but I so not sure exactly what it is?

Best Answer

If the carrier frequency is 20 Khz, then your fixed step size must be less then 0.00005. I will set fixed step size=0.000005