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

Abstract

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-mu m standard CMOS process dissipates 12.6 mW from a 1.8-V supply voltage.