A 2.2-mW Backgate Coupled <formula formulatype="inline"> <tex>$LC$</tex></formula> Quadrature VCO With Current Reused Structure

Abstract

This letter presents a backgate coupled quadrature voltage-controlled oscillator (QVCO) which consists of a pair of current reused LC-VCOs. The proposed QVCO is designed for 2-GHz operation based on a 0.18-mum triple-well CMOS technology. Measurements show -102 and -124dBc/Hz at 100-kHz and 1-MHz offset, respectively. Compared to the conventional QVCO, the proposed QVCO dissipates significantly lower power (1.74mA from a 1.25-V supply) while showing good 1/f <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> close-in phase noise