A low phase noise and wide tuning range voltage-controlled oscillator (VCO) operating at 10GHz and a mixed design of current mode logic (CML) divider is designed and fabricated in TSMC 0.13-um CMOS technology. The VCO achieves a wide tuning range of 27.5%(9.1 GHz to 11.9GHz), and provides an output power of -3dBm, while drawing 10mA from 1.3V power supply. The measured output phase noise is -116.4 dBc/Hz at 1MHz offset frequency from the carrier frequency of 10.15GHz. The VCO figure of merit is a record low -188 dBc/Hz. The chip area is 0.688×0.724 (mm2).