G{sub}m-Boosted Common-Gate LNA and Differential Colpitts VCO/QVCO in 0.18-μm CMOS

摘要

The demand for radio frequency (RF) integrated circuits with reduced power consumption is growing owing to the trend toward system-on-a-chip (SoC) implementations in deep-sub-micron CMOS technologies. The concomitant need for high performance imposes additional challenges for circuit designers. In this paper, a g{sub}m -boosted common-gate low-noise amplifier (CGLNA), differential Colpitts voltage-controlled oscillators (VCO), and a quadrature Colpitts voltage-controlled oscillator (QVCO) are presented as alternatives to the conventional common-source LNA and crossrcoupled VCO/QVCO topologies. Specifically, a g{sub}m -boosted common-gate LNA loosens the link between noise factor (i.e., noise match) and input matching (i.e., power match); consequently, both noise factor and bias current are simultaneously reduced. A transformer-coupled CGLNA is described. Suggested by the functional and topological similarities between amplifiers and oscillators, differential Colpitts VCO and QVCO circuits are presented that relax the start-up requirements and improve both close-in and far-out phase noise compared to conventional Colpitts configurations. Experimental results from a 0.18-μm CMOS process validate the g{sub}m -boosting design principle.