Design and Performance Analysis of Active Inductor Based Voltage Controlled Oscillator in 90nm CMOS Process for Wireless Applications

Abstract

This thesis represents the effective design of voltage controlled oscillator which is an integral part of modern RF communication system for varying output frequency with respect to input voltage. In this research ,the indispensable effecting parameters of designing VCO was anatomized properly with view to proceeding the research steps in a beneficial way and comparative analysis of different active inductor models was performed in an efficacious way. In addition, simulations of different active inductors were executed using cadence 6.16 environment which ease to depict the high performing active inductor in insightful research perspective. The simulation results showed the variation of performance of different active inductor models regarding quality factor, power consumption, inductance tunability and frequency range. It highly perspicuous from the simulation results that Weng-Kuo active inductor is superior to other established models due to high quality factor of(4.263@0.9GHz and 2.23 @2.7 GHz) as well as wide frequency range having a value of (7.462 GHz and 11.868GHz). Power consumption was also in optimum level with tenability of inductance and quality factor independently. These facts intrigued to apply Weng-kuo active inductor for designing a VCO which would show satisfactory frequency range for Bluetooth applications, low phase noise and higher figure of merit with respect to the other cited works . The simulations of our designed VCO was performed via cadence 6.16 environment which has illustrated the performance appropriately .The oscillator yielded a differential output of 0.48 to-0.448 mV @ 2.4GHz and a tuning range of 2.17 GHz to 2.72GHz with a variation of control voltage of 0 V to .8 V. For Vcontrol = 0.4V, the frequency is 2.40887 GHz with a phase noise of -82.34 dBc/Hz@1MHz offset and power consumption was 4.18761 mW. The performance parameters exhibits stability with variation of control voltage along with a high power output that outperforms the other referred works. Performance comparison with several previously designed VCOs clinched that our designed VCO shows unique properties of consuming low power, stability and high power output which indicates the high power efficiency. ABSTRACT