An Ultra Wide Tuning Range VCO with Active Tunable Inductors

This paper presents the design of an ultra-wideband CMOS VCO with tuning range of 3.8 similar to 7.4GHz, using a modified tunable active inductor (TAI) in a 0.18um CMOS technology. The inductance of TAI, with nearly a quality factor of 90, can be tuned from 0.34 to 0.61 nH. The power dissipation is about 29mW and phase noise is -92dBc/Hz. PLL-based and LC-based phase noise reduction techniques are examined, reducing the phase noise by 1dBc/Hz and 3dBc/Hz, respectively. Monte Carlo simulations illustrate the robustness of the oscillator performance under reduced bias voltage, temperature change, and process variations. Finally, the effect of packaging is investigated through simulations and modeling of ad and bonding wire, which show that only the upper frequency capability is degraded by 6% while the phase noise will experience slight improvement. Copyright (C) 2008 Praise Worthy Prize S.r.l - All rights reserved.