An ultra-wideband and gain linearized CMOS VCO with minor phase noise variation

An ultra-wideband CMOS LC tank voltage-controlled oscillator with low phase noise variations and a gain linearized varactor bank is proposed and characterized in this paper. The proposed VCO has been designed using UMC 130nm, 6-metal CMOS technology and features phase noise variation of less than 4.9 dBc/Hz. The VCO operates from 3.45 GHz to 6.54 GHz, with phase noise of −133.2 dBc/Hz at a 1 MHz offset, a figure of merit (FoM) of −203.4 dBc/Hz, less than −37 dBm spurious harmonics, and a total VCO core current consumption of 1.3 mA from a 3.3 V voltage supply. To the authors' knowledge, this is the lowest phase noise variation ever reported.