A low-voltage low-phase-noise C-band 0.18-µm CMOS VCO with L-type matching network

A low-voltage low-phase-noise fully-integrated 0.18-μm CMOS voltage-controlled oscillator (VCO) is presented in this paper. A proposed L-type matching network is utilized in the VCO to enhance the overall loop gain. Moreover, by using the voltage swing boosted technique, the VCO can operate at low supply voltage with comparable performance. Based on this design methodology, the fabricated 0.18-μm CMOS VCO can operate at a measured 0.62-V low supply voltage. At this bias condition, the measured phase noise at 1-MHz offset from 5.23-GHz carrier is -119.6 dBc/Hz, and the measured tuning range is 6.0%. Compared to recently published 0.18-μm C-band CMOS VCOs, this work demonstrates the lowest supply voltage and comparable figure-of-merit (FOM).