Simultaneous amplitude and phase approximation for lumped and sampled filters

A simultaneous amplitude and phase approximation method is presented for reciprocal and non-reciprocal lumped or sampled filters realized by LC, CCD, active RC, cascaded SC, digital or wave digital IIR filters. The approximation is based on the fictive decomposition of a non-minimum phase filter into a minimum phase and an allpass network in such a way that some poles and zeros should coincide with each other and so the filter order should decrease. In this way the amplitude and phase approximations can be carried out alternately, though the minimum phase and the allpass networks do not occur in the resulting filter