A 7.8-to-10.7GHz Reliable-Mode-Switching Series Resonance Oscillator with Bidirectional Inductive-Mode-Pulling Achieving -156.5 dBc/Hz Phase Noise and 199.2dBc/Hz FoMT at 10MHz Offset in 40-nm CMOS

This paper proposes a reliable-mode-switching series resonance oscillator with bidirectional inductive-mode-pulling to achieve ultra-low phase noise and wide tuning range, simultaneously. The connection of mode switches are designed to avoid large parasitic capacitance and voltage swing. The bidirectional inductive-pulling transformer is introduced to expand the frequency range of both even and odd modes without reliability risk. Meanwhile, the balanced-slope NMOS inverter is introduced to minimize the common mode ripple and ensure the virtual ground for mode switching. Prototyped in a 40-nm CMOS process, the measured VCO exhibits merits of 31.6% FTR from 7.8 to 10.7 GHz, -156.5dBc/Hz phase noise, and 199.2dBc/Hz FoMT at 10MHz offset.