A wideband LC-VCO with small VCO gain variation and adaptive power control

<正>A wideband LC tank voltage-controlled-oscillator（VCO） is proposed.To solve the impacts of wideband operation on VCO gain(KVCO) variation and start-up constraint,a binary-weighted varactor array and a binary-weighted negative resistance array all with optimal unit values are designed.Implemented in a 0.18μm CMOS process,the proposed VCO shows a frequency tuning range from 1.9 to 3.1 GHz,with a current consumption varying accordingly from 14.2 to 4 mA from a 1.8 V supply.With the proposed KVCO suppression technique,the KVCO varies from 50 to 60 MHz/V in the entire frequency range.The measured phase noise is -117 dBc/Hz at a 1 MHz offset from a 3 GHz carrier.