A Low Phase-Noise QVCO With Integrated Back-Gate Coupling and Source Resistive Degeneration Technique

A 0.18 mum CMOS quadrature voltage-controlled oscillator with an extremely-low phase noise is presented. The excellent phase noise performance is accomplished by integration of the back-gate quadrature phase coupling and source resistive degeneration techniques into a complementary oscillator topology. The measured phase noise is as low as -133 dBc/Hz at 1 MHz offset from 3.01 GHz. The output phase imbalance is less than 1^deg . The output power is -1.25plusmn 0.5 dBm and harmonic suppression is greater than 30.8 dBc. The oscillator core consumes 5.38 mA from a 1.5 V power supply. This QVCO achieves the highest figure-of-merit of -193.5 dBc/Hz.