butterworth low filter

Discussion in 'Homework Help' started by vead, May 5, 2014.

  1. vead

    Thread Starter Active Member

    Nov 24, 2011
    621
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    butterworth low filter

    specification

    passband cut off frequency
    stopband- cut off frequency
    passband ripple
    stopband attenuation
    sampling frequency


    how to identify by the given specification that its low pass, high pass,band pass or band stop filter
     
  2. PRS

    Well-Known Member

    Aug 24, 2008
    989
    35
    I'm not sure I understand your question. Are you asking for a definition of these terms? Butterworth data tables are usually accompanied by a schematic. If you could post one then ask a question about it there are plenty of people here who will help you.
     
  3. WBahn

    Moderator

    Mar 31, 2012
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    Uh... butterworth low filter might give a hint.
     
  4. vead

    Thread Starter Active Member

    Nov 24, 2011
    621
    8
    butterworth digital filter
    passband-0-500 hz
    stopband-2-4 khz
    passband ripple-3 db
    stopband attenuation-20 db
    sampling frequency-8 khz

    how to identify by the given specification that its low pass, high pass,band pass or band stop filter
     
  5. WBahn

    Moderator

    Mar 31, 2012
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    If it isn't glaringly obvious to you, perhaps you should go back and reread what each filter type means and then review what each of the specifications means.
     
  6. vead

    Thread Starter Active Member

    Nov 24, 2011
    621
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    Fp = passband cut off frequency
    Fs= stopband cut off frequency

    case I - low pass filter

    Fp<Fs

    case II - high pass filter

    Fs<Fp

    case III - band pass filter

    Fs1<Fp1 , Fp2<Fs2

    case IV band stop filter

    Fp1<Fs1 , Fs2< Fp2

    It will be low pass filter because Fp<Fs 500Hz<4khz
     
  7. vead

    Thread Starter Active Member

    Nov 24, 2011
    621
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    check out this work
     
  8. WBahn

    Moderator

    Mar 31, 2012
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    If I tell you that a filter has a pass band that ranges from 0 Hz to 1000 Hz, do I really need to tell you anything else for you to determine what type of filter it is?
     
  9. vead

    Thread Starter Active Member

    Nov 24, 2011
    621
    8
    I think I need stop band frequency
     
  10. WBahn

    Moderator

    Mar 31, 2012
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    Why?

    Give me an example of a stop band frequency that would make it a high pass filter? Or a stop band frequency that would make it a band pass filter?
     
  11. vead

    Thread Starter Active Member

    Nov 24, 2011
    621
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    case II - high pass filter

    Fs<Fp

    case III - band pass filter

    Fs1<Fp1 , Fp2<Fs2
     
  12. WBahn

    Moderator

    Mar 31, 2012
    17,743
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    So, give me an EXAMPLE of an Fs for a filter whose pass band is 0 Hz to 1000 Hz that would make it either a high pass filter or a low pass filter. Start thinking and stop being an equation monkey.
     
  13. KD4FNC

    New Member

    May 11, 2014
    1
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