Quadrature oscillator/universal filter using CCCII with adjustable gain

This paper presents a quadrature oscillator and universal filter using current controlled current conveyor with adjustable gain as active element. The proposed circuit combines a quadrature oscillator and a universal filter without changing the topology. In the case that the circuit works as a quadrature oscillator, two quadrature voltage outputs and four quadrature current outputs can be obtained. The condition of oscillation and frequency of oscillation can be orthogonally controlled. In the case that the circuit works as a universal filter, low-pass, band-pass, high-stop, band-stop, and all-pass filtering functions can be obtained. The natural frequency and quality factor of filters can be electronically controlled. The proposed topology is simulated using PSPICE simulators to confirm the workability of the new circuit.