A comparison of MOS varactors in fully-integrated CMOS LC VCO's at 5 and 7 GHz

@article{Ainspan2000ACO,
  title={A comparison of MOS varactors in fully-integrated CMOS LC VCO's at 5 and 7 GHz},
  author={Herschel A. Ainspan and J. O. Plouchart},
  journal={Proceedings of the 26th European Solid-State Circuits Conference},
  year={2000},
  pages={447-450}
}
This paper examines the effect of the choice of MOS varactor on the performance of a CMOS negative resistance oscillator. The three most common MOS varactor structures (inversion, accumulation, and gated varactor) are combined with a spiral inductor over either deep trench oxide or a polysilicon patterned ground shield, to implement a matrix of six LC VCO's in a 0.24-µm (0.18- µm Leff) SiGe BiCMOS technology[1]. Typical measured VCO phase noise is -119.7 dBc/Hz at a 1-MHz offset from a 5.67-GHz… CONTINUE READING