An 8.2 GHz triple coupling low-phase-noise class-F QVCO in 65nm CMOS

An 8.2 GHz low-phase-noise Class-F quadrature voltage controlled oscillator (QVCO) is presented. With the proposed triple coupling technique, the oscillation frequency of the QVCO is only determined by the inter-stage passive matching components, and the introduced third harmonic at the drain of the transistors help form the approximately square voltage waveform to achieve low impulse-sensitivity function (ISF) value, which results in good phase noise performance and good quadrature phase accuracy. Implemented in 65nm CMOS, the QVCO shows a measured phase noise of -120.86 dBc/Hz at 1 MHz offset from 7.76 GHz carrier frequency (188.4 dBc/Hz FoM value), and a measured quadrature phase error of 0.72°. The QVCO consumes 10.6-12.3 mW power from one 0.6 V supply and 0.38mm² active die area.