A single-amplifier biquad active filter

A single-amplifier circuit is introduced and shown to be capable of realizing any second-order minimum-phase voltage transfer function while maintaining an isotopic structure. Sensitivity analysis demonstrates that the single-amplifier biquad (SAB) is comparable to other state-of-the-art active filters employing more amplifiers. A bandpass SAB together with an extra amplifiers enables the realization of right-half-plane zeros.