Impulse invariance and multiple-order poles

摘要

The impulse-invariant method of IIR digital filter design from a given analog filter is useful both in filter design and especially in discrete-time simulation of continuous-time systems. The article clarifies aspects of impulse invariance and, in particular, the handling of multiple-order poles. The user is currently faced with incorrect formulas and Matlab software. The problems are discussed, and a method valid for any order poles is presented via a numerical example using original Matlab code.