Generalised approach for active-RC quadrature oscillator circuit with grounded capacitors

Abstract

This study introduces a new approach for realising a sinusoidal oscillator with three outputs, using an active-resistor-capacitor (RC) approach. Using the proposed approach, a new circuit employing three current feedback operational amplifiers and passive components is further introduced. The circuit employs two grounded capacitors and four resistors, out of which one is grounded. The new circuit based on the proposed generalised approach is relatively insensitive to the parasitic effects of active elements, and easy to design, by way of non-interaction of frequency and condition of oscillations. The proposed approach and the new proposed circuit provide three outputs, two of which are at low impedance nodes. The proposed generalised approach and the new circuit are verified through simulation and experimental results, using commercially available AD-844s integrated circuits and passive components. Thus, the work advances the existing knowledge on the active-RC oscillator design.