Exp-5 Digital Butterworth IIR Filter Design

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This experiment taught me that:

  • Stability of the filter is decided by the placement of analog poles on the s-plane. If the poles lie on the left-side of the plane, filter is completely stable.
  • There are two methods to design IIR filters: Bilinear Transformation Method(BLT) and Impulse Invariant Method(IIM).
  • IIM method gives many-to-one mapping.Hence it is not suitable for HPF and BPF filter design.
  • Butterworth filter design was done using Scilab and MATLAB software.

Comments

  1. Gopala15 May 2018 at 07:10

    What happens if the poles are at origin?

    ReplyDelete
    Replies
    1. Unknown15 May 2018 at 21:16

      This comment has been removed by the author.

      Delete
    2. Unknown15 May 2018 at 23:55

      filter will become stable

      Delete
  2. Unknown15 May 2018 at 07:42

    BLT method is more suitable for designing Butterworth filters.

    ReplyDelete
  3. Anonymous15 May 2018 at 08:03

    It's also important to note that Butterworth filters are "maximally flat", making them good candidates for approximating ideal filters well

    ReplyDelete
  4. Anonymous15 May 2018 at 08:51

    It is worth noting that IIR filters are better than FIR filters as they typically meet a given set of specifications with a much lower filter order than a corresponding FIR filter.

    ReplyDelete
  5. Unknown15 May 2018 at 19:32

    How do we design FIR filters then?

    ReplyDelete

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