pros and cons of digital filters

Discussion in 'Wireless & RF Design' started by Mahsoub, Sep 22, 2014.

  1. Mahsoub

    Thread Starter New Member

    Jun 8, 2011
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    I am interested first in a simple comparison of analog & digital filters in general as to frequency response , hardware requirements, delay, limitations of both filters,....etc, and in general their pros and cons. I am much obliged if anyone can help me with this comparison or guide me to sources of such matter but rather simple concise ones not the mathematical theory. Second I would like an emphasis on digital filters as regards to their limitations and drawbacks in particular.
    Regards and many thanks
     
  2. Papabravo

    Expert

    Feb 24, 2006
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    Is there something in particular you are curious about? The reason I ask is that understanding what is going on without groking the mathematics is just about impossible.
     
  3. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
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    Digital filters are generally more reproducible and can be made a lot more complex than conventional filters. Silicon is always cheaper than copper! However, there are a few places where analog filters will be around a long time. One is in UHF and microwave applications. Another is in high powered R.F. applications. It's unlikely any digital filter will replace a 100KW lowpass filter. :)

    Eric
     
  4. Papabravo

    Expert

    Feb 24, 2006
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    No digital filter can perform the band limiting, anti-aliasing function.
     
  5. Mahsoub

    Thread Starter New Member

    Jun 8, 2011
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    I am more interested in digital filters limitations and drawbacks.
    Thanks
     
  6. alfacliff

    Well-Known Member

    Dec 13, 2013
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    is it possible that he is refering to "interdigital filters" instead of solid state ones?
     
  7. shteii01

    AAC Fanatic!

    Feb 19, 2010
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    It is possible that this is a homework asignment.
     
  8. Mahsoub

    Thread Starter New Member

    Jun 8, 2011
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    something of this sort
     
  9. Mahsoub

    Thread Starter New Member

    Jun 8, 2011
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    I m referring to the digital filters that i read of at the text books, if you can reply to my inquiry please do. thx
     
  10. Papabravo

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    Feb 24, 2006
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    I already mentioned that they can't be used for the anti-alias function.
    They are limited to low frequencies by the need to use very high sampling rates for very high frequencies.
    The can produce outputs when there is no input.
    Doing bandpass and notch functions is more difficult than with analog filters

    Is that enough?
     
  11. Mahsoub

    Thread Starter New Member

    Jun 8, 2011
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    Thanks for your reply.
     
  12. alfacliff

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    Dec 13, 2013
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    frequency conversion can get the signals down to where they can be digitized with minimum problems. after digitizing, use math functions to simulate any kind of filter you want. then D/A to get the output.
     
  13. Mahsoub

    Thread Starter New Member

    Jun 8, 2011
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    Thanks for your comments. One thing I forgot to ask, is what are the points that I should consider when comparing the two filters? I know of linearity, phase response, steepness between cut and pass ranges. If you can, please suggest others.
    Thanks.
     
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