Skip to Main Content
A new quadrature VCO is designed in a standard UMC 0.13 mu m CMOS process with low voltage, low power and low phase noise. Diodes are employed to generate second-harmonic coupling between the common sources of two LC VCOs for quadrature outputs. At 1-V supply and at 3.9 GHz, the QVCO measures phase noise of -117dBc/Hz at 1-MHz offset while dissipating 7.5 mA which corresponds to a figure of merit of 180 dBc. The core area is 0.37 mm2.