1 May 2020

Advantages and disadvantages of IIR filter

IIR filter is typically used in a system that uses digital signal processing. IIR filter includes the Butterworth, vessel, and Chebyshev filter. These filters are typically in audio applications such as the speakers and for sound processing functions. Here this article gives information about the advantages and disadvantages of the IIR filter to better understand this topic.

Advantages of IIR filter

  • IIR filter is better than the FIR in that, it can produce the same response using some fewer delay blocks. 
  • It is easy to implement.
  • It is easy to design.
  • This filter is useful only when some analog filter is bandlimited.
  • They are harder to implement using fixed-point arithmetic, such as noise generated by calculations and also limit cycles.
  • They are more susceptible to the problem of line finite length arithmetic.
  • An IIR filter has a lesser number of side lobes in the stopband than an FIR filter.
  • They don't offer the computational advantages of the FIR filter for the multi-rate application system.
  • Implementation of IIR filter involves fewer parameters, less memory requirement, and lower computational complexity.
Disadvantages of IIR filter
  • There are more susceptible to the problem of finite length arithmetic, Such as the noise is generated by calculations, and limit cycle. 
  • They are harder to implement using fixed-point arithmetic.
  • IIR filter becomes unstable.
  • Lower computational complexity.
  • Analog frequency and digital frequency are linearly related.
  • IIR filters usually have a non-linear response, while the FIR usually has a linear phase.
  • They don't offer the computational advantages of the FIR filter for multi-rate applications.
  • IIR filter has a feedback loop so they will accumulate rounding and noise error.
  • An IIR filter has a lesser number of side lobes in the stopband.
  • The realization of the IIR filter is not very easy as compared to FIR filters.
  • The implementation of an IIR filter involves fewer parameters needed.
  • Less memory requirement.
  • It is a recursive filter the number of the coefficient is very large and the memory requirement is also high.
  • It is hard to optimize than the FIR filter.