A MINIATURE CMOS VCO WITH SYMMETRIC TRACE DIFFERENTIAL STACKED SPIRAL INDUCTOR

Abstract

In this study, a miniature silicon-based symmetric trace differential stacked spiral inductor (SDSSI) was used in the design of a voltage controlled oscillator (VCO) using standard 0.18 mu m CMOS technology. The SDSSI has a high self-resonance frequency (f(sr)) and quality factor (Q) in spite of using the stacking technique, because the parasitic capacitance between the layers is reduced by alternatively locating traces at different positions in each layer. The output power spectrum and phase noise of the designed VCO is -0.79 dBm and 114 dBc/Hz at 1-MHz offset frequency, respectively. The oscillation frequencies cover from 1.84 GHz to 2.38 GHz with a tuning range of 26%, while the occupied on-chip area of the VCO is only 350 x 450 mu m(2).