Amplitude Modulation

[helios1]

Which is the best choice for a carrier signal in amplitude modulation? A sine or square? and why?

 

[Harald Kapp]

A sine, of course.
If you use any other waveform, you will create sidebands at the harmonics of the carrier frequency.
1) you will have to filter (remove) these side bands, otherwise you will disturb other signals.
2) you put energy into these sidebands that is lost for the main purpose, because it gets filtered (see 1).

Using a sine as carrier gives you the most bang for the buck, so to speak.

Harald

 

[helios1]

Thanks Harald!