Weighted complementary IIR digital filters
Markku Renfors, Sushmita Mitra, P.A. Regalia, Yrjo A. Neuvo · 1991
The authors examine the properties of weighted complementary IIR (infinite impulse response) filters utilizing either real or complex conjugate allpass subfilters. A generalized structure where the allpass branches include arbitrary real or complex weighting constants is discussed. Applications of these weighted complementary filters include gain equalizers, digital filters with multilevel magnitude response, and sharpening the amplitude response of digital filters realized as a cascade of identical filter stages.>