Envelopedetektorit

Envelopedetektorit are electronic circuits designed to extract the envelope of a modulated signal. The envelope represents the varying amplitude of a carrier wave, which typically carries information in amplitude modulation (AM) systems. These detectors are crucial for demodulating AM signals, allowing the recovery of the original audio or data signal.

A common method for constructing an envelopedetektor involves a diode and a capacitor in parallel, often with a resistor in series. The diode rectifies the incoming modulated signal, allowing current to flow only in one direction. The capacitor then charges up to the peak voltage of the rectified signal. As the amplitude of the modulated signal decreases, the capacitor discharges through the resistor. The resistor's value is chosen to be large enough so that the capacitor does not discharge too quickly between peaks of the carrier wave, but small enough to follow the slower variations of the envelope. The output voltage across the capacitor then approximates the envelope of the original signal.

Variations of envelopedetektorit exist, including those that use active components like transistors or integrated circuits for improved performance, such as higher sensitivity and better linearity. These circuits are fundamental in radio receivers and other communication systems where amplitude modulation is employed. The primary function remains the isolation and reproduction of the signal's amplitude variations.