A 2-GHz low-phase-noise integrated LC-VCO set with flicker-noiseupconversion minimization

摘要

A fully integrated 2-GHz very low-phase-noise LC-tanknvoltage-controlled oscillator (VCO) set with flicker noise upconversionnminimization is presented. Using only integrated planar inductors, thenmeasured phase noise is as low as -125.1 dBc/Hz at 600-kHz offset andn-138 dBc/Hz at 3 MHz. The excellent phase-noise performance is achievednby means of an in-house-developed integrated inductor simulatornoptimizer. To minimize the upconversion of flicker noise to 1/f3n phase noise, a flicker-noise upconversion factor is defined,nwhich can easily be extracted from circuit simulation. The technique isnapplied to demonstrate the relationship between the flicker-noisenupconversion and the overdrive level of the oscillators' MOSncross-coupled pair and to develop circuit balancing techniques to evennfurther reduce the flicker-noise upconversion. The 1/f3nphase-noise corner is minimized to be less than 15 kHz. The VCO's arenimplemented in a three-metal layer, 0.65-Μm BiCMOS process, usingnonly MOS active devices