Amplitude modulation

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AMPLITUDE MODULATION (AM)
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AMPLITUDE MODULATION (AM)

• Amplitude of the carrier is varied in proportion
  to the instantaneous amplitude of the information
  signal or AF signal
• Amplitude (intensity) of the cw is changed but
  not its frequency
• Greater the amplitude of AF signal greater will
  be the variation in the amplitude of the cw

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AMPLITUDE MODULATION (AM)
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AMPLITUDE MODULATION (AM)
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MODULATOR

• Function of modulator is to mix these two waves
  in such a way that AF signal is transmitted along
  the cw
• Stations broadcasting on the standard broadcast
  band (535 1605 kHz) use AM modulation
• The envelope of the modulated carrier wave is an
  exact copy of the AF signal wave

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AMPLITUDE MODULATION (AM)
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RECAPITULATION

• Amplitude Modulation
• Modulator

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• What is the function of modulator ?
• What is the frequency of am ?
• What is AM ?

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FREQUENCY MODULATION