DESIGN OF QUASI-EQUIRIPPLE IIR FILTERS WITH PRESCRIBED FLATNESS AND APPROXIMATELY LINEAR PHASE

摘要

In this paper, we propose a method for designing quasiequiripplerninfinite impulse response (IIR) filters with prescribedrnflatness and approximately linear phase characteristics.rnIn the proposed method, the flatness condition inrnstopband is preincorporated into the transfer function andrnthe design problems are formulated as an iterative quadraticrnprogramming (QP) problem. The flatness condition inrnpassband is added to the QP problem as the linear matrixrnequality. As a result, the proposed method can designrnthe IIR filters which have an equiripple response and prescribedrnflatness in passband or stopband or both. Finally,rnwe show some design examples and confirm the effectivenessrnof the proposed method.