A 0.3 V Cross-Coupled VCO Using Dynamic Threshold MOSFET

Abstract

An ultra-low voltage differential voltage-controlled oscillator (VCO) is designed and implemented in a 0.13 ? m CMOS 1P8M process. The designed circuit topology is an nMOS-core cross-coupled LC-tank VCO, and a self-generated 2nd harmonic ac signal is coupled to the bodies of MOSFETs to enhance the VCO performance. At the supply voltage of 0.3 V, the output phase noise of the VCO is -116.88 dBc/Hz at 1 MHz offset frequency from the carrier frequency of 3.579 GHz, and the figure of merit is -194.43 dBc/Hz. Total power consumption is 0.225 mW. Tuning range is about 240(770) MHz, from 3.39 to 3.63(4.16) GHz, while the control voltage was tuned from 0 V to 0.3(1.0) V.