Editing Envelope detector (section)

=== AM demodulation ===
Envelope detectors can be used to [[demodulate]] an [[amplitude modulated]] (AM) signal. Such a device is often used to demodulate AM [[radio signal]]s because the envelope of the modulated signal is equivalent to the [[baseband]] signal. To sufficiently attenuate the frequency of the [[carrier wave]] frequency <math>f_\text{carrier}</math>, the cutoff frequency of the low-pass filter should be well-below the carrier wave's frequency. To avoid negative peak clipping, the original signal that is modulated is usually limited to a maximum frequency <math>f_\text{max}</math> to limit the maximum rate of fall of the AM signal. To minimize distortions from both ripple and negative peak clipping, the following inequality should be observed:<ref name=":0" />

<math display="block"> \frac{1}{f_\text{carrier}} \ll \tau \ll \frac{1}{f_\text{max}} \; .</math>

Next, to filter out the DC component, the output could pass through a simple high-pass filter, such as a DC-blocking capacitor.