CCII-based single-element controlled quadrature oscillators employing grounded passive components

A single resistance-controlled two-phase quadrature oscillator using plus-type second generation current conveyors CCIIs(+) as the active devices is realized by using a simple technique. The basic building blocks for this technique are a firstorder all-pass filter section and an ideal integrator. The quadrature oscillator is then transformed into a four-phase quadrature oscillator by replacing the two CCII(+) by two dual-output current conveyors (DO-CCIIs) with two grounded resistors. Both the realized circuits enjoy attractive features such as use of grounded passive components, independent frequency control, outputs of equal magnitude and low sensitivity figures. The use of grounded passive components make the circuit suitable for monolithic implementation. The proposed circuits are designed and verified using Pspice simulation.