A Transformer-Feedback Quadrature Voltage-Controlled Oscillator Using a Transconductance Tuning Technique

This paper presents a transformer-feedback quadrature voltage-controlled oscillator (QVCO) using a transconductance tuning technique in 0.18-um CMOS process. The proposed topology uses integrated transformers to produce quadrature phase and employ a transconductance tuning technique for frequency tuning. The measured phase noise is -101 dBc/Hz _~ -104dBc/Hz at 1-MHz offset. The tuning range is from 5.97 GHz to 6.81 GHz, achieved by the control voltage from -0.9 V to 0.9 V. The measured phase error of the QVCO is below 2.2deg. The power consumption is 8.44 mW _~ 17.88 mW and the figure of merit (FOM) is -167.3_~ -168 dB.