A 25 GHz quadrature voltage controlled ring oscillator in 0.12/spl mu/m SiGe HBT

A 25 GHz ring VCO is fabricated in a 0.12mum SiGe BiCMOS process. The VCO with a 3.3V supply consumes 32mA. The measured phase noise is -105dBc/Hz at 10MHz offset from the center frequency of 24.3 GHz. Design optimization techniques for high performance ring oscillators in a 0.12 mum SiGe HBT technology are discussed