A low power wide tuning range VCO with coupled LC tanks

A 12GHz VCO fabricated in a 0.18µm SiGe BiCMOS technology with only CMOS devices, is presented. To improve tuning range and phase noise, a technique using strongly magnetic coupled LC tanks with fixed and tunable capacitive elements is proposed. The VCO achieves wide tuning range of 4.3GHz (36%) with only 4.5mW power consumption. The proposed VCO including buffer stage occupies a chip area of 0.17mm
²
, and can be easily integrated on-chip with other blocks.