Narrow BP active-RC filters with reduced power and sensitivity

This paper presents the low-sensitivity and low-power realization of narrow high-order band-pass (BP) active resistance-capacitance (RC) filters. It is known that filters using multiple-feedback structures have reduced sensitivities to passive component tolerances. We present a filter realization using cascaded "two-amplifier biquartic" BP active filter blocks (CBQ), with reduced numbers of operational amplifiers. The "impedance tapering" and the gain-sensitivity-product minimization decrease both passive and active sensitivities of biquartic blocks. As an example, the design procedure and the Schoeffler´s sensitivity analysis, were performed for an 8th-order Chebyshev narrow-BP filter.