A Low-Noise Class-F ₂₃ VCO With Harmonic Resonance Expansion and 2nd/3rd-Harmonic Outputs for Multiband mm-Wave Applications

This paper presents a low-noise class-F<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">23</sub> voltage-controlled oscillator (VCO) with harmonic resonance expansion and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2^{\mathrm {nd}}$</tex-math> </inline-formula>/<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3^{\mathrm {rd}}$</tex-math> </inline-formula>-harmonic outputs for multiband mm-wave applications. By using a single four-coil transformer to extend the common-mode (CM) and differential-mode (DM) harmonic resonance bandwidths, the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2^{\mathrm {nd}}$</tex-math> </inline-formula>- and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3^{\mathrm {rd}}$</tex-math> </inline-formula>-harmonic resonances can be acquired without additional frequency alignment calibration. Meanwhile, benefiting from the favorable differential response at the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2^{\mathrm {nd}}$</tex-math> </inline-formula>- and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3^{\mathrm {rd}}$</tex-math> </inline-formula>-harmonic frequencies, the corresponding harmonic frequency outputs are extracted, simultaneously. Fabricated in 65-nm CMOS process, the proposed VCO achieves a frequency tuning range (FTR) of 20.8% from 10.71 GHz to 13.20GHz with 1-MHz offset phase noise (PN) from -117.4 to -114.5 dBc/Hz, while consuming 7.8-9.8 mW at 0.6 V. The VCO core area is only 0.054 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and the flicker noise corner is 310-450 kHz. The figure-of-merit (FoM) at 10-MHz offset scores 189.8-191.7 dBc/Hz. The harmonic outputs achieve a FTR of 21.42-26.40 GHz and 32.13-39.60 GHz, with a 1-MHz-offset PN from –110.5 to –107.5 dBc/Hz and –107.6 to –104.8 dBc/Hz.