1. A digital filter is described by the following difference equation. determine if this is an IIR or FIR filter. Explain your answer.

Question

Y[n] = 0.25x[n] + 0.5x[n-1] + 0.25x[n-2] - 1.2y[n-1] + 0.2y[n-2]
Filter Type:
a) IIR filter
b) FIR filter

Answer 1

This is an IIR filter because it has feedback terms involving previous outputs. In this case, the terms involving y[n-1] and y[n-2] indicate that the filter is recursive in nature, hence making it an IIR filter.