A 6-13.5GHz Wideband Single-Core LC VCO with Lookup Table Algorithm

A wideband LC voltage controlled oscillator using a single core is presented in this paper. The proposed VCO covers frequency range from 6GHz to 13.5GHz and will be implemented in 65nm CMOS process. Switched capacitance arrays and MOS varactors acting as coarse and fine tune units determine the wide tuning range 76.9%. By dividing the whole frequency range into 8 sub frequency bands, lookup table (LUT) algorithm is proposed to achieve the fast lock of the PLL. The tuning gain Kvco is adjusted smaller to acquire better phase noise at high frequency and Kvco is digital controlled between 100 MHz/V to 600MHz/V at 13GHz, therefore the phase noise of the VCO is -113dBc/Hz at 1MHz offset and differences are less than 1dBc/Hz@1MHz at all frequency bands. The power supply is 1.2V and programmable biasing current varies from 4mA to 26mA.