In this case, the *mixer* is doing amplitude modulation, not the PLL. The OP asked if a PLL could function as an AM Modulator, which is no.What happens if you take a baseband signal such as the raw data signal and mix it with the carrier frequency coming out of the PLL? Doesn't that just translate the baseband signal to the carrier, thus producing sidebands that are replicas of the baseband signal? Isn't that AM?
Edit 1So,means that PLL only can be used in angle modulation? If I want to design frequency modulator by using LM567,any reference for the circuit design?
Some phase detector designs used in PLLs are basically mixers, so that piece of it could be used as an amplitude modulator. Of course this isn't universally true, it only applies to a limited set of phase detector designs. Maybe that is what she's referring to.I have no idea on this.I think my lecturer means that she used the PLL as AM modulator in her research.
Of course, *most* people would call that Phase Modulation (PM). But, if the professor is indeed calling AM = Angle Modulation, then we can conclude two things:PLL Applications: http://www.mit.bme.hu/eng/system/files/oktatas/targyak/8527/Lab2_M9_PLL_application.pdf
It seems that by AM everyone is interpreting as Amplitude Modulation. What if! They mean Angle Modulation...
Also I see many links for AM DEMODULATION with PLL.
Nothing about MODULATION.