Infinite Impulse Response (IIR) Digital Filters

Abstract

In Chap. 3 we introduced the FIR filter. The most important properties that make the FIR attractive (+) or unattractive (−) for selective applications include:

• FIR linear-phase performance is easily achieved.

• Multiband filters are possible.

• The Kaiser window method allows iterative-free design.

• FIRs have a simple structure for decimators and interpolators (see Chap. 5).

• Nonrecursive filters are always stable and have no limit cycles.

• It is easy to get high-speed, pipelined designs.

• FIRs typically have low coefficient and arithmetic roundoff error budgets, and well-defined quantization noise.

• Recursive FIR filters may be unstable because of imperfect pole/zero annihilation.

• The sophisticated Parks-McClellan algorithms must be available for minimax filter design.

• High filter length requires high implementation effort.