A low power, small area, fully integrated 5.5GHz CMOS LC-VCO

An integrated 5.5 GHz low power voltage-controlled oscillator (VCO) has been designed and implemented in a 250 nm CMOS process. This cross-coupled LC VCO achieves measured phase noise of about 90 dBc/Hz at an offset frequency of 1MHz and a power consumption of less than 2.1 mW. The output frequency of the VCO can be tuned from 5.19 GHz to 6.12 GHz, which correspond to a 16.9% tuning range, obtained by tuning the control voltage of the varactor. The VCO output power remains nearly constant over the entire tuning range.