A 18.8 GHz Noise Circulating VCO With Implicit Noise Filter for Quantum Computing

An 18.8 GHz noise circulating VCO with implicit common-mode resonance is implemented using TSMC 90-nm CMOS technology for spin-qubit quantum computing. The VCO covers the tuning range of $18.74-18.8 \mathrm{GHz}$. It achieves the phase noise of $-131.5 \mathrm{dBc} / \mathrm{Hz}$ at a $10-\mathrm{MHz}$ offset and the figure-of-merit (FOM) of $\mathbf{- 1 9 0. 8 ~ d B c / H z}$ by consuming the power of 4.08 mW.