A 2.34–3.29GHz CMOS LC VCO with low phase noise and low power

A low phase noise wideband LC VCO is designed and presented. In this VCO, a symmetrical LC tank with proper arrangement of varactors is used to extend its tuning range. Results from the post layout simulation show that the VCO achieved a wide tuning range from 2.34GHz to 3.29GHz. Moreover, a noise cancellation technique is adopted to achieve better phase noise performance. The VCO exhibits that phase noise is lower than -120.1dBc/Hz at 1-MHz offset frequency. The circuit consumes 2.38mA of power from a 1.8V supply.