Investigation and Optimization of Low-Power Techniques in X-Band CMOS LC-VCO Design

Abstract

This paper investigates the optimization method for two low-power circuit techniques in low-power LC-VCO designs: Transformer feedback and forward body-bias. In addition to theoretical analysis, a low-power, low-voltage X-band VCO using these two techniques has also been implemented in a standard 0.18 mu m CMOS technology. This VCO exhibits good FOM and of -191.4dBc/Hz while the core circuit draws a DC current of 2.73mA from 0.55V low supply voltage. The excellent performance can be compared with the best reported X-band CMOS VCOs.