1) Detector 2) Rectifier 
device for recovering the original modulating signal from an oscillation or wave produced by modulationa device for recovering the original modulating signal from an oscillation or wave produced by modulation Examples of demodulators: amplitude demodulator; linear demodulator or envelope demodulator; frequency demodulator; phase demodulator; pulse demodulator; coherent demodulator or synchronous demodulator.
A device that separates the signal from the carrier frequency onto which it was modulated.
noun rectifier that extracts modulation from a radio carrier wave