Fully-monolithic SiGe differential voltage-controlled oscillator for 5 GHz wireless applications

A fully integrated and differential SiGe VCOs was designed for 5 GHz wireless applications. The measured phase noise is -98 dBc/Hz at 100 kHz offset off the 5 GHz carrier. It has a tuning range of 12.3% with a control voltage from 0 to 3V, and a figure of merit of more than -180 dBc/Hz. The current drawn from 3V is 5 mA for the core and 2.2 mA for the output buffers.