Study on Use of Diodes As Demodulators and Power Conversion: The Role of Diodes in Demodulation and Power Conversion

Abstract

An AM signal consists of alternating positive and negativepeaks of a radio carrier wave,whose amplitude or envelope is proportional to the originalaudio signal. The diode (originally a crystal diode) rectifies the AMradio frequency signal, leaving only the positive peaks of the carrier wave.The audio is then extracted from the rectified carrier wave using a simplefilter and fed into an audio amplifier or transducer, which generatessound waves. Rectifiers are constructed from diodes, where they are usedto convert alternating current (AC) electricity into directcurrent (DC). Automotive alternators are a common example, wherethe diode, which rectifies the AC into DC, provides better performance thanthe commutator or earlier, dynamo. Similarly, diodes are alsoused in Cockcroft–Walton voltagemultipliers to convert AC into higher DC voltages.