demodulation

Demodulation, also referred to as detection, is the recovery of the modulation signal from a modulated carrier signal.

In demodulation, depending on the modulation method, the modulated carrier signals are converted back into the modulation signals by removing the carrier signal and then rectifying it in a demodulator. Before demodulation takes place, the carrier frequency is preselected and mixed with a local oscillator frequency. The resulting frequency, called the intermediate frequency, still contains the modulation signal. This is separated from the carrier signal after selective amplification in a rectifier.