Diode Envelope Detector | Amplitude Modulation AM Demodulation

The diode detector has been used for many years for detecting or demodulation signals using amplitude modulation, AM. The AM diode detector offers simplicity and low cost. The circuit for the AM diode detector uses a diode, capacitor and a load resistor which is often the volume control for the audio stages.

The video looks at the characteristics of a diode and how this can be used to rectify the amplitude modulated signal to recover the audio. The way in which the detection or demodulation process operates is shown in an easy to understand fashion.

The AM diode detector circuit is also used as a peak detector for RF signals where again its simplicity is a great advantage.

In the video we also look at what amplitude modulation is: how the amplitude of the signal varies in line with the modulating audio signal.

Amplitude modulation is mainly used for broadcasting on the long, mediaum and short wave bands. It has been used since the beginning of the twentieth century and is still in use today.

[tomatrix]

This was EPIC. I was looking for so long how the demodulation actually works, rather than the explanation that it is ‘passed through a demodulator’ (DUHhh BUT HOW LOL) finally, you did it my friend

[cosminbel]

knee voltage is different than forward voltage...
good explanation of AM 👍

[ashishtayade]

Thank you sir very nice gide & very nice best information diode detector video..👍

[ankajgarg]

Concept of demodulation simplified in just two minutes....

[MaxBilimoria]

can you clarify if the AM signal is carrying data/audio in Sine Wave when it reaches the detector (diode) and is removing half the signals amplitude isn’t that then loss of data or audio as a consequence? or is the data only actually enveloped in the positive side of the wave….? Or is that in the AM the data is duplicated on both sides of the sine wave?…. Your answer on this would be greatly appreciated?

[acqurius-gxlr]

is there any criteria for selecting carrier frequency based on modulating frequency

[TheGmr]

very nice, in our world of dsp, this is now done by mag of iq data or taking hilbert transform of a signal and getting the mag of the signal

[drstrangelove]

Have you considered not saying the "nought" (or zero) when saying values floating point numbers like "0.6"? It's really not needed.

[kamleshchavan]

Circuit diagram of RF signal, mixture circuit

[hehk]

This does nothing to explain how one half of the signal can be heard. Why doesn't it sound like SSB, where half the waveform is also thrown away?