Title :
Fully integrated 5.35-GHz CMOS VCOs and prescalers
Author :
Hung, Chih-Ming ; Floyd, Brian A. ; Park, Namkyu ; Kenneth, K.O.
Author_Institution :
Florida Univ., Gainesville, FL, USA
fDate :
1/1/2001 12:00:00 AM
Abstract :
Two 5.35-GHz monolithic voltage-controlled oscillators (VCOs) and two prescalers have been fabricated in a digital 0.25-μm CMOS process. One VCO uses p+/n-well diodes, while the other uses MOS varactors, Q of 57 at 5.5 GHz and 0 V bias (low-Q condition) for a p +/n-well varactor has been achieved. For an MOS varactor, it is possible to achieve a quality factor of 140 at 5.5 GHz. The tuning ranges of the VCOs are >310 MHz, and their phase noise is <-116.5 dBc/Hz at a 1-MHz offset while consuming ~7 mW power at VDD=1.5 V. The low phase noise is achieved by using only PMOS transistors in the VCO core and by optimizing the resonator layout. The prescalers utilize a variation of the source-coupled logic. The power consumption is 4.1 mW at 1.5-V VDD and 5.4 GHz. By widening the transistors in the first three divide-by-two stages, the maximum operating frequency is increased to 9.96 GHz at VDD=2.5 V
Keywords :
CMOS analogue integrated circuits; CMOS logic circuits; MMIC oscillators; Q-factor; circuit tuning; field effect MMIC; integrated circuit design; logic design; prescalers; varactors; voltage-controlled oscillators; 0.25 micron; 1.5 V; 4.1 mW; 5.35 to 5.5 GHz; 7 mW; CMOS VCOs; CMOS prescalers; MOS varactors; VCO core; core PMOS transistors; digital CMOS process; fully integrated devices; low phase noise; monolithic voltage-controlled oscillators; p+/n-well diodes; p+/n-well varactor; quality factor; resonator layout optimisation; source-coupled logic; tuning ranges; CMOS process; Diodes; Energy consumption; Logic; MOSFETs; Phase noise; Q factor; Tuning; Varactors; Voltage-controlled oscillators;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on