A Colpitts Current-Reused QVCO Based on Capacitor Coupling

Abstract

This paper presents a Colpitts current-reused quadrature voltage-controlled oscillator (QVCO) based on capacitor coupling in TSMC 0.18um CMOS 1P6M process technology. Comparing to conventional parallel-coupled QVCO (P-QVCO), the proposed QVCO achieves a better phase noise and phase accuracy. The proposed QVCO operates from 4.57GHz to 5.02GHz. The measured phase noise at 1MHz offset frequency is -119 dBc/Hz and the measured phase error of quadrature signals arc 5 at 5CHz. With 1.8V power supply, the power consumption is 8.46mW. The figure of merit (FOM) of proposed QVCO is 183.7 dBc/Hz. The die area is 1x0.78mm(2)