A 2.4GHz CMOS Quadrature VCO for 2.4GHz WLAN/Bluetooth Applications

A 2.4GHz low-phase-noise and low-phase-error LC tank quadrature voltage controlled oscillator (QVCO) using the parasitic vertical BJT coupling and RC phase shifters is presented. Based on the proposed techniques, the proposed QVCO can simultaneously have low phase noise and low phase error. This QVCO circuit has been realized in a 0.18mum triple-well CMOS process and exhibits below 0.2deg phase error with phase noise of -105dBc/Hz at 100kHz offset frequency. The tuning range is 380MHz from 2.27GHz to 2.65GHz with control voltage from 0.3V to 1.8V. It consumes 5.4mW at each tank