Summary: For wireless communication, a low-voltage monolithic LC-tank CMOS voltage-controlled-oscillator (VCO) is developed with 0.2-µm fully-depleted silicon-on-insulator (SOI) CMOS process technology. The VCO features a double-tuning technique to achieve a wide tuning range with lateral p-n junction varactors. The VCO has the following features at the supply voltage of 1.5 V: (1) Output frequency range from 1.07 GHz to 1.36 GHz, (2) Third-harmonic below -37 dBc, and (3) Phase noise of -120 dBc/Hz at 1 MHz offset frequency.