Analysis of half-band approximately linear phase IIR filter realization structure in MATLAB

Abstract

In this paper a detailed analysis of an atypical filter structure in MATLAB Filter Design and Analysis (FDA) Tool is presented. As an example of atypical filter structure, the IIR half-band filter with approximately linear phase realized as a parallel connection of two all-pass branches was examined. We compare two types of those filters obtained by two different design algorithms. FDA tool was used for the experiment because different effects of the fixed point implementation can be simulated easily. One of the goals of this paper was to compare results obtained by two different design algorithms. In addition, different realizations of the filter structure based on the parallel connection of two all-pass branches were examined.