A fully integrated VCO and divider implemented in SMIC 0.13-μm RFCMOS 1P8M technology with a 1.2 V supply voltage is presented.The frequency of the VCO is tuning from 8.64 to 11.62 GHz while the quadrature LO signals for 802.11a WLAN in 5.8 GHz band or for 802.11b/g WLAN and Bluetooth in 2.4 GHz band can be obtained by a frequency division by 2 or 4,respectively.A 6 bit switched capacitor array is applied for precise tuning of all necessary frequency bands.The testing results show that the VCO has a phase noise of-113 dBc @ 1 MHz offset from the carrier of 5.5 GHz by dividing VCO output by two and the VCO core consumes 3.72 mW.The figure-of-merit for the tuning-range(FOM_T) of the VCO is -192.6 dBc/Hz. A fully integrated VCO and divider implemented in SMIC 0.13-μm RFCMOS 1P8M technology with a 1.2 V supply voltage is presented. The frequency of the VCO is tuning from 8.64 to 11.62 GHz while the quadrature LO signals for 802.11a WLAN in 5.8 GHz band or for 802.11b / g WLAN and Bluetooth in 2.4 GHz band can be obtained by a frequency division by 2 or 4, respectively. A 6 bit switched capacitor array is applied for precise tuning of all necessary frequency bands.The testing results show that the VCO has a phase noise of -133 dBc @ 1 MHz offset from the carrier of 5.5 GHz by dividing the VCO output by two and the VCO core consumption 3.72 mW. The figure-of-merit for the tuning-range (FOM_T) of the VCO is -192.6 dBc / Hz.