A synthesis of low‐sensitivity digital filters using t‐casade connection

When we realize a digital filter, a low-sensitivity structure is desired to produce less degradation of characteristics in finite word length. In addition, for the fast operation, a structure that can be parallelized or pipelined is preferable. The low-sensitivity digital filter, a wave digital filter proposed by Fettweis, is well known. Taking into consideration the fore-mentioned, we propose synthesis of a digital filter that will permit pipeline processing and possess low-sensitivity as in a wave digital filter. First we show that a circuit structure using T-cascade connection of basic sections allows pipeline processing; we then derive a method for synthesis of a digital filter having this form of structure from a given transfer function in z-domain. Then in the proposed method we demonstrate synthesis of not only IIR filters but also FIR filters in a unified fashion. A realization of basic sections used in circuit synthesis is shown and the effectiveness of our synthesis method is verified by examples.