A 20GHz VCO with 5GHz tuning range in 0.25 /spl mu/m SiGe BiCMOS

This paper presents a 20 GHz VCO with 5 GHz tuning range in 0.25 /spl mu/m SiGe BiCMOS. A differential capacitive emitter degenerated structure is used as a negative resistance cell that has extremely low parasitic capacitance. The VCO core consumes 9 mW, and the measured phase noise at 1 MHz offset is -101.2 dBc/Hz.