Design of equiripple stopband even and odd order linear phase IIR filters
Tsuyoshi Takebe, Tatsunori Matsumoto, Shuitsu Matsumura, Kyoto Kato · 2002
This paper presents a method for designing even and odd order, equiripple stopband, arbitrary passband amplitude, perfect linear phase IIR transfer functions with mirror image pole pairs around the unit circle in the z-plane. Starting from a suitable nonlinear phase subfilter, the perfect linear phase transfer function is derived using an auxiliary allpass function in the transformed frequency domain. Design examples of passband flat amplitude lowpass filters are also shown.