An Ultra-Low-Power 65 nm Single-Tank 24.5-to-29.1 GHz G_m-Enhanced CMOS LC VCO Achieving 195.2 dBc/Hz FoM at 1 MHz

A low-power single-core 24.5-to-29.1 GHz CMOS LC voltage-controlled oscillator (VCO) is presented. The proposed VCO uses an innovative differential cross-coupled architecture in which an additional pair is connected to the main pair to increase the effective transconductance, resulting in lower power consumption and reduced phase noise (PN). The proposed VCO is fabricated in a 1P9M standard CMOS process and sustains oscillation at 29.14 GHz with power consumption as low as 455 mu W (650 mu A from a 0.7 V supply), which is similar to 20% lower than a conventional CMOS LC VCO without G(m)-enhanced differential pairs built through the same process (700 mu A from 0.8 V supply). When consuming 880 mu W (1.1 mA from 0.8 V), the proposed VCO exhibits a tuning range of 4.6 GHz (from 24.5 GHz to 29.1 GHz). Moreover, it exhibits a measured phase noise (PN) better than -106.5 dBc/Hz @ 1 MHz and -132.0 dBc/Hz @ 10 MHz, with figure-of-merit (FoM) results of 195.2 dBc/Hz and 200.3 dBc/Hz, respectively.