Design and Analysis of a 0.4V 1.08mW 12GHz High-Performance VCO in 0.18μm CMOS (Invited Paper)

This paper presents the design and analysis of a high-performance fully-integrated 0.18μm CMOS voltage-controlled oscillator (VCO) with low supply voltage and low dc power consumption. To enhance the transconductance (gm) of MOSFETs and negative conductance (-Gm) of a cross-coupled pair, the device size of the nMOS cross-coupled pair is enlarged. For reducing the supply voltage and minimizing the dc power consumption, forward-body biased technique is utilized in this VCO, leading to the threshold voltage (Vt) reduction. Moreover, process variations are taken into accounted at low supply voltage, and the Monte-Carlo analysis is used to analyze the VCO phase noise and output power. At 0.4V low supply voltage, the fabricated 0.18μm CMOS VCO consumes 1.08mW low core power. At this bias condition, the measured phase noise at 1MHz offset from 12.77GHz carrier is -110.2 dBc/Hz, and the measured tuning range is 5.75%. Compared to recently published 0.18μm X-band CMOS VCOs, this work demonstrates the low supply voltage, low dc power dissipation, superior figure-of-merit (FOM), and better figure-of-merit including the tuning range (FOMT).