A Harmonic-Tuned VCO With an Intrinsic-High-<i>Q</i> F<sub>23</sub> Inductor in 65-nm CMOS
Peng Yu, Longlong Zhou, Yiming Yu, Huihua Liu, Yunqiu Wu, Chenxi Zhao, Hongyan Tang, Kai Kang
Abstract
A harmonic-tuned (HT) voltage-controlled oscillator in a 65-nm CMOS process is demonstrated in this letter. The oscillation frequency and harmonics are tuned independently by two separated high-Q resonators. A novel F <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">23</sub> inductor-capacitor resonator resonating at the second and third harmonics simultaneously is introduced. The proposed F <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">23</sub> inductor has a high-quality factor of 15 and 24 in common-mode (CM) and differential-mode (DM), respectively. The simulation results show that a 4.3-dB phase noise (PN) improvement is achieved in the thermal noise region due to the high-Q HT method. Meanwhile, less harmonic currents are injected into the fundamental resonator due to the source-degeneration principle, hence decreasing the Groszkowski effect and suppressing the flicker noise. The measured PN is -117.5 dBc/Hz at the 1-MHz offset, and the tuning range is 12% from 6.80 to 7.66 GHz. The flicker noise corner is around 220 kHz and the figure-of-merit is 187.2 dBc/Hz. The power consumption is 5 mW under a 0.55-V supply.