27-GHz low phase-noise CMOS standing-wave oscillator for millimeter wave applications

This work presents a 27-GHz low phase-noise standing-wave voltage controlled oscillator (VCO) design with the folded microstrip line structure over floating metal strips. Because the floating metal strips serve to retard the wave, the length of microstrip line (and thus the overall layout area) can be further reduced at a given frequency. Meanwhile, the floating metal strips reduce the substrate effect and improve the Q-factor of the microstrip line. The measurement results exhibit a tuning range from 26.26 GHz to 26.80 (27.55) GHz with the tuning voltage rising from 0.1 V to 1.8 (3.3) V. The measured phase-noise levels are around -115 dBc/Hz and -134 dBc/Hz at 1-MHz and 10-MHz offset, respectively. The DC power consumption of the oscillator core is 17.7 mW at the supply voltage of 1.8 V. The figure of merits (FOM) of this VCO is -191 dB.