Operational Current Amplifier-Based Quadrature Oscillators Family

Quadrature oscillators are essential circuits in communication systems, signal processing, and instrumentation where two sinusoidal signals with a 90° phase difference are required. Conventional voltage-mode designs often face limitations in terms of bandwidth, linearity, and power efficiency. To address these challenges, this project presents the design and analysis of a family of quadrature oscillators based on Operational Current Amplifiers (OCAs). The proposed circuits operate in the current-mode domain, offering wide frequency tuning ranges, low-voltage operation, and high output linearity. Multiple oscillator topologies are developed and compared to demonstrate flexibility in design while maintaining quadrature accuracy. The circuits are evaluated in terms of oscillation frequency, total harmonic distortion (THD), power consumption, and phase accuracy. Simulation results using standard CMOS technology validate the effectiveness of OCA-based implementations, showing significant improvements in performance compared to traditional approaches. The work establishes a scalable and energy-efficient framework for current-mode quadrature oscillator design suitable for modern VLSI and communication applications.