Wide tuning range cmos millimeter‐wave vco using resistors‐added mosfet varactor

This article presents a CMOS millimeter‐wave voltage‐controlled oscillator (VCO), which provides a wide tuning range using a resistors‐added MOSFET varactor.Large resistors connected to the source and bulk allow a MOSFET varactor to lower minimum capacitance and to maintain maximum capacitance compared to a conventional MOSFET varactor. Thus, the total capacitance tuning range of the proposed varactor is expanded to ±46.1%, allowing a VCO with the new varactor to possess a frequency tuning range of 13.4% from 29.3 to 33.5 GHz. The measured phase noise is −97.8 dBc/Hz at a 1‐MHz offset at the center frequency of 31.3 GHz. The VCO in a 0.18‐μm standard CMOS process dissipates 12.6 mW from a 1.8‐V supply voltage. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1777–1783, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26983