A dual-resonance CMOS voltage-controlled oscillator with enhanced performance through new varactor topology

A new fully integrated, dual-band CMOS voltage controlled oscillator (VCO) is presented. The VCO is composed of a p-core cross-coupled and an n-core cross-coupled Colpitts oscillator with dual-resonance LC tank and was implemented in 90-nm CMOS technology with 1.15 V supply voltage. The circuit allows the VCO to operate at two resonant frequencies with a common LC tank. This VCO is configured with 6.3 and 10 GHz frequency bands with differential outputs. The dual-band VCO operates at 6.11–6.413 GHz and 9.72–10.24 GHz. The phase noises of the VCO operating at 9.72 and 6.4 GHz are −116.31 dBc/Hz and −122.79 dBc/Hz at 1-MHz offset, respectively, while the VCO draws 4/4.28 mA and 4.6/4.92 mW consumption at high/low frequency band from a 1.15-V supply. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1590–1593, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26882