A 3.5 GHz low‐power and phase noise differential CMOS VCO

Abstract

AbstractA novel low‐power differential Colpitts voltage‐controlled oscillator (VCO) is proposed and implemented in a 0.18‐μm CMOS 1P6M process. The proposed circuit topology consists of two single‐ended Colpitts LC‐tank VCOs, and the differential VCO is obtained by using a cross‐coupled nMOS pair. At the supply voltage of 1.8 V, the output phase noise of the VCO is −120.56 dBc/Hz at 1 MHz offset frequency from the carrier frequency of 3.64 GHz, and the figure of merit is −185.9 dBc/Hz. Total power consumption is 3.8 mW. Tuning range is about 487 MHz, from 3.64 to 3.15 GHz, while the control voltage was tuned from 0 to 1.8 V. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 153–156, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23003