Amplitúdómoduláció

Amplitúdómoduláció, often abbreviated as AM, is a modulation technique used in electronic communication, most notably in the broadcasting of radio signals. It involves varying the amplitude of a carrier wave in proportion to the information being transmitted. Imagine a steady, high-frequency wave, like a pure musical note. In AM, the loudness (amplitude) of this note is made to change according to the sound you want to send. When the original sound signal is loud, the carrier wave's amplitude increases; when the sound is quiet, the carrier wave's amplitude decreases.

The process consists of a carrier wave and a message signal. The carrier wave is a high-frequency signal that is always present. The message signal, which contains the information to be transmitted (like voice or music), is used to modify the amplitude of the carrier wave. A device called a modulator performs this operation. At the receiving end, a demodulator extracts the original message signal from the modulated carrier wave by detecting these amplitude variations. AM is relatively simple to implement and was one of the earliest forms of radio transmission. However, it is susceptible to noise and interference, which can also affect the amplitude of the signal, leading to distortion of the received message. Despite its limitations, AM remains in use for certain applications, particularly in long-wave and medium-wave radio broadcasting due to its ability to travel long distances.