15 DEFINE NOISE , SIGNAL TO NOISE RATION ,NOISE FIGURE ,NOISE TEMPERATURE

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NOISE : -  Noise is an unwanted energy signal ,with combines with the original message signal and change the properties of message signal .

  • Noise is added majorly in the '' modulation section ''of transmitter .


S/N RATIO :-  It is ration of signal power to the noise power .

  • S/N RATIO = signal power / noise power
  • if S/N ration is high noise is less.
  •  FM had more s/n ration then AM.


NOISE FIGURE :- It is defined as the ration of signal to noise ration in-put to signal to noise ratio output

  • N.F = (S/N) INPUT  /  (S/N) OUTPUT


NOISE TEMPERATURE :-It is the noise added due to heat , the heat maybe produced    due to electronic components or climatic conditions




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