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.