A dual/wide band quadrature VCO with programmable LC tank for quad-band direct conversion WCDMA/WLAN receiver

A dual/wideband quadrature VCO is designed using TSMC 0.25 /spl mu/m CMOS process. Its programmable on-chip LC tank provides 50% and 15.7% tuning range for each operating band. The VCO successfully covers all WCDMA and WLAN frequency range, while providing moderate phase noise performance.