Amplituudmodulaator

An amplituudmodulaator, or amplitude modulator, is an electronic circuit or system that varies the amplitude of a carrier wave in accordance with the instantaneous amplitude of a modulating signal. This process is fundamental to many forms of analog communication, particularly in radio broadcasting. The carrier wave is a high-frequency signal that is transmitted over the air, while the modulating signal is the information to be sent, such as audio.

In amplitude modulation (AM), the amplitude of the carrier wave is directly proportional to the amplitude of the modulating signal. This means that when the modulating signal's amplitude increases, the carrier wave's amplitude also increases, and when the modulating signal's amplitude decreases, the carrier wave's amplitude decreases. The frequency and phase of the carrier wave remain constant throughout the modulation process.

The simplest form of an amplituudmodulaator can be constructed using a nonlinear device, such as a diode or a transistor, followed by a filter. The nonlinear device mixes the carrier wave and the modulating signal, producing a sum and difference frequency component, as well as other harmonics. A bandpass filter is then used to extract the desired modulated signal, which typically consists of the carrier frequency and two sidebands containing the information from the modulating signal.

Amplituudmodulaator circuits are essential for transmitting information wirelessly. They allow for the encoding of various types of data onto a carrier wave, which can then be efficiently propagated through the atmosphere. While simpler to implement and decode than some other modulation schemes, AM is also more susceptible to noise and interference, which can distort the amplitude variations and lead to a degraded signal quality.