A Stacked-Complementary 5 GHz Oscillator With Even-Only Differential Harmonic Shaping Achieving −150 dBc/Hz Phase Noise at 10-MHz Offset Using Body-Biased Thin-Oxide 22-nm FDSOI

Abstract

This letter proposes a 5-GHz stacked-complementary oscillator (SCO) that uses high-quality factor ( $Q$ ) single-turn nested differential inductors to achieve very low tank fundamental impedance $R_{\mathrm{ Tank}}$ and even-harmonic shaping. The complementary nature of nMOS and pMOS is exploited to achieve second and fourth harmonic common-mode resonances using differential-only inductors with higher $Q$ compared to the conventional single-ended tail filter. The complementary-stacked topology ensures the voltage between any two device terminals remains within reliable limits, while the body-bias is used to set the oscillator class with much lower noise sensitivity compared to the standard gate biasing. The SCO achieves < −150 dBc/Hz phase noise at 10-MHz offset across the tuning range from 4.75 to 5.4 GHz and a supply frequency pushing better than 20 MHz/V, while using thin-oxide devices operated from 0.6 V in a 22-nm technology node. The SCO meets the stringent phase noise requirements of the GSM standard while keeping a figure-of-merit (FoM) of 191–193 dBc/Hz at 10-MHz offset.