低次IIRディジタルフィルタによる直線位相FIRディジタルフィルタの振幅と位相の近似

抄録

This paper compares the time and memory requirements of an approximately linear phase IIR digital filter with those of a linear phase FIR digital filter, and shows that, only if a substantial difference between the orders of the filters exists, the former can be considered as an attractive substitute for the latter. Furthermore, it presents a method which makes feasible the design of reduced-order IIR digital filters that resemble the characteristics of a linear plase FIR digital filter. Some design examples are shown, illustrating how the proposed method can be used to design approximately linear phase IIR digital filters that are faster and require less memory than their equivalent linear plase FIR counterparts.