Electronically Tunable VDCC-Based Third-Order Quadrature Oscillator

This paper presents the design and analysis of a third-order quadrature oscillator using Voltage Differencing Current Conveyors (VDCCs). The proposed circuit generates stable quadrature outputs with a 90-degree phase difference at a target frequency of approximately 106kHz where the THD drops to approximately 1.2. PSPICE simulations were conducted to validate the oscillator's performance, demonstrating steady-state behavior, consistent amplitude, and minimal harmonic distortion. The design’s electronic tunability, achieved by adjusting bias currents, enables precise frequency control, making it suitable for applications in signal processing and communications. The simulation results confirm the oscillator's potential for integration into modern electronic systems requiring reliable, low-distortion quadrature signals.