An UWB CMOS voltage‐controlled oscillator with 2–6 GHz tuning‐range using active inductor technology

An ultra‐wideband voltage‐controlled oscillator (VCO) in a standard 0.18‐μm CMOS process is presented in this article. The designed VCO adopts two active inductors to replace the passive spiral inductors; this results in an increase in tuning‐range and chip area reduction. The active inductor provides a variable inductance range from 1.7 to 3.6 nH, so that the output frequencies of the novel VCO can be obtained from 2 to 6 GHz, with a tuning‐range of around 100%. According to the experimental result, it indicates that the proposed design exhibits a significant wide tuning‐range and compact chip size compared with a standard VCO with passive inductors. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2311–2315, 2008; Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/mop.23655