A 2.4 GHz Very Low Phase Noise Fully Integrated Quadrature LC Oscillator

This paper presents a quadrature voltage-controlled oscillator (QVCO) based on the coupling of two LC-tank VCOs. The QVCO could be tuned between 2.41 and 2.64 GHz, and showed a phase noise of-139 dBc/Hz at 1 MHz offset frequency from the carrier across the whole tuning range, for a current consumption of 20 mA with 2.5-V power supply. A figure-of- merit of-190 dBc/Hz is observed.