A wide frequency tuning range active-inductor voltage-controlled oscillator for ultra wideband applications

This paper presents a new active inductor LC-tank voltage-controlled oscillator with an ultra wide frequency tuning range. The large frequency tuning range is obtained by varying the inductance of the active inductor. Two inductance tuning mechanisms, namely the wide-band tuning mechanism for coarse frequency adjustment over a large frequency range for band selection and the primary tuning mechanism for the fine frequency tuning in frequency synthesis, are introduced. The proposed oscillator was designed and implemented in TSMC-0.18 mum 1.8V 6-metal 1-poly CMOS technology. The oscillator occupies a small active area of 85 times 50 mum². The wide-band tuning mechanism provides a frequency tuning range from 0.2 GHz to 6.5 GHz while the primary tuning mechanism provides a frequency range from 1.4 GHz to 1.7 GHz when the center frequency of the oscillator is set to 1.6 GHz. The phase noise with the VCO tuned to 1.6 GHz is -118.5 dBc/Hz at 1 MHz frequency offset.