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Anti-Aliasing Filter

  1. Sep 21, 2006 #1

    Can anyone tell me what an anti-aliasing filter is and how it is used?


  2. jcsd
  3. Sep 21, 2006 #2


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    Aliasing is an undesired effect in the use of analog-to-digital converters. Frequency components above the the Nyquist band (above half the sampling frequency) get "mirrored" into lower frequencies inside the Nyquist band. Once a high frequency has been aliased, there is no way to distinguish it from a real low-frequency signal.

    An anti-aliasing filter is a low-pass filter, put before the ADC, that attenuates frequency components above the Nyquist band.

    - Warren
  4. Sep 22, 2006 #3
    Thanks. I appreciate it.
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