# How harmonics happens when you mix two signals?

Doing a search in quora about Why does Amplitude Modulation have sideband frequencies? i found an answer and within it, a user answered with the following statement:

"When you try mixing two signals, there will be something know as harmonics that will occur. This means that frqncy X (+) Frqncy Y will not just form frequency Z but some more frequencies that will be embedded into the system."

Can someone clarify and or exemplify the statement?

• The statement can’t be clarified because it is ambiguous (does not specify the type of mixing, linear or non-linear, AM or other, nor the frequencies), and thus is very likely outright wrong. – hotpaw2 Sep 16 '20 at 5:53

• There is one case I can think of where harmonics appear in mixing: when a sinusoid of frequency $\omega_1$ modulates another sinusoid also of frequency $\omega_1$. Then, the resulting frequencies are $0$ and $2\omega_1$. – Peter K. Sep 14 '20 at 21:31
• @Fat32 yes agreed rereading the post, the harmonics associated with the non linearities are the reason other frequencies beyond $f_c+ f_m$ and $f_c-f_m$ appear but they have nothing to do with why AM has sidelobes which are those two components alone - so that other user’s comment she quoted is somewhat misplaced. I see why you made that point and why that comment would cause her confusion. – Dan Boschen Sep 15 '20 at 12:04