A 2.5-GHz Low Phase Noise BAW-based Oscillator in 65nm CMOS Process

This paper reports a miniaturized 2.5-GHz oscillator using a high-Q bulk acoustic wave (BAW) resonator. The cross-coupled topology is adopted to suppress power supply variations and enhance output swing. The oscillator achieves an outstanding phase noise performance of -143dBc/Hz and -153dBc/Hz at 1MHz and 10MHz offset, respectively. The integrated RMS jitter (12kHz to 20MHz) is 112fs. Measured power consumption is 670μW at 1V supply voltage. The figure-of-merit (FoM) of the oscillator is 213dB@1MHz. A divide-by-8 frequency divider is introduced to provide an output frequency of 315MHz.