Magnitude and Phase Approximation of IIR Digital Filters Using Linear Programming

Toshiyuki YOSHIDA  Akinori NISHIHARA  Nobuo FUJII  

IEICE TRANSACTIONS (1976-1990)   Vol.E72   No.10   pp.1097-1103
Publication Date: 1989/10/25
Online ISSN: 
Print ISSN: 0000-0000
Type of Manuscript: PAPER
Category: Digital Signal Processing

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This paper discusses a new simultaneous design method of both magnitude and phase of IIR digital filters. It is inherently a nonlinear problem to approximate the magnitude and phase of an IIR digital filter simultaneously. In this paper, however, such a nonlinear problem is converted into a linear one by vector rotation method and solved by the linear programming (LP) technique. As a result our method requires no initial guesses for any type of filter specifications. A stable digital filter is designed which approximately satisfies the linearity of the phase in the pass band and the given attenuation in the stop band. The design examples given in this paper shows the usefulness of the proposing method.