Amplitude modulation is a type of modulation where the carrier signal’s amplitude is varied in accordance with the information bearing signal.
The amplitude modulated signal’s envelope or boundary embeds the information bearing signal.
The total power of the transmitted signal varies with the modulating signal, whereas the carrier power remains constant.
A nonlinear device combines the carrier and the modulating signal to generate an amplitude modulated signal. The nonlinear device’s output consists of discrete upper and lower sidebands.
A nonlinear device’s output does not vary in direct proportion with the input.
Amplitude Modulation is abbreviated AM.