A Class-F23 VCO with Implicit Common-Mode Resonance Expansion

This paper presents a novel harmonic-shaping Class-F23 voltage-controlled oscillator (VCO) with implicit common-mode (CM) resonance expansion. By adding single-ended capacitors to the gate node of the Gm transistors, the proposed VCO achieves common-mode resonance expansion. Implemented in a 65-nm CMOS process, the VCO achieves phase noise lower than -117.4 dBc/Hz at 1-MHz offset and figure-of-merit (FoM) higher than 189.6 dBc/Hz at 1-MHz offset over the entire tuning range.