A 600 \mu W BAW-Tuned Quadrature VCO Using Source Degenerated Coupling

A bulk-acoustic wave (BAW)-tuned quadrature voltage-controlled oscillator (BQVCO) designed in 0.13 mum CMOS is presented. The BQVCO operates at 2.1 GHz, with a power consumption of 600 muW at a 1 V supply. The oscillator achieves a phase noise of -143.5 dBc/Hz at 1 MHz offset with a figure of merit (FOM) of 212.1 dB. A new time-varying source degeneration coupling mechanism has been used to quadrature-couple the two oscillator cores for I/Q signal generation, reducing the required headroom of the series coupling transistors. A binary weighted capacitor array is designed for fine frequency tuning of the QVCO. For comparison, an identical QVCO with on-chip LC tank is fabricated, achieving a FOM of 179.7 dB.