Characteristic setting method for digital filter

Abstract

Abstract PURPOSE:To obtain the digital filters of various filter characteristics by adding some element of a certain type to the filter coefficient. CONSTITUTION:For instance, the frequency conversion formula is shown as Eq. (4) at region Z for conversion of the cut-off frequency of LPF. Here, alpha means the frequency conversion parameter and is shown as Eq. (5), where beta is the cut-off frequency of the prototype filter and omegac is the same cut-off frequency after conversion. Thus if parameter alpha is applied to the circulation-type digital filter of multi-step bicut structure, the transmission function H'[Z] becomes as shown in Eq. (7). With this transmission filter, the digital filter is formed by securing the mutual connection among the adder circuit, the 1-sample delay circuit, the multiplier circuit and the divider circuit each.

Inventors

• 👤 Tadamichi Kawasaki

Bibliographic Details