AM demodulation

Learning objectives

To illustrate the principle behind an envelope detection circuit and to show its limits.
To illustrate the influence of the time constant in a capacitative discharge.

It is because demodulation of an amplitude modulated (AM) signal is so simple that this type of modulation has existed for so long. The fabrication of a simple envelope detection circuit like that shown in this simulation is very simple and not costly.

Nonetheless, the rectification provided by a commutation diode produces some distortion, and this type of circuit is no longer used in high quality receivers.