Explain detection of amplitude modulated wave.
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Detection is the process of recovering the amplitude modulated wave from the channel. For detecting the wave an antenna is used which catches the wave. Once the wave is received, it is passed through an amplifier.
While transmission the amplitude modulated wave is attenuated, hence amplification of the wave is mandatory. Amplification is followed by intermediate filter stage, which filters out all the unwanted signals from the wave. After filter stage, amplitude modulated wave is forwarded to a detector (tuner) which tunes the wave to the required frequency.
After tuning, the wave is again amplified and passed over to the rectifier. Rectifier is a device which allows the current to follow only in one direction i.e. rectifier allows the propagation of wave only in the positive direction and will eliminate the wave in negative direction. The output wave from the rectifier only contains the positive cycle of the wave.
After rectification, the wave reaches to envelop detector. Envelop detector is a capacitor with high resistance. Capacitor allows the high frequency wave to pass through and will block the low frequency wave. When the high frequency wave will pass through the capacitor, it will be short circuited and the low frequency wave will pass through the resistance and that gives the original message wave as the output.
While transmission the amplitude modulated wave is attenuated, hence amplification of the wave is mandatory. Amplification is followed by intermediate filter stage, which filters out all the unwanted signals from the wave. After filter stage, amplitude modulated wave is forwarded to a detector (tuner) which tunes the wave to the required frequency.
After tuning, the wave is again amplified and passed over to the rectifier. Rectifier is a device which allows the current to follow only in one direction i.e. rectifier allows the propagation of wave only in the positive direction and will eliminate the wave in negative direction. The output wave from the rectifier only contains the positive cycle of the wave.
After rectification, the wave reaches to envelop detector. Envelop detector is a capacitor with high resistance. Capacitor allows the high frequency wave to pass through and will block the low frequency wave. When the high frequency wave will pass through the capacitor, it will be short circuited and the low frequency wave will pass through the resistance and that gives the original message wave as the output.
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Amplitude modulation AM is amodulation technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. In amplitude modulation, the amplitude signalstrength of the carrier wave is varied in proportion to the waveform being transmitted.
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