A 78-microwatt GSM phase noise-compliant pierce oscillator referenced to a 61-MHz wine-glass disk resonator

Abstract

A 61-MHz Pierce oscillator referenced to a single polysilicon surface-micromachined wine-glass disk resonator has achieved phase noise marks of -119dBc/Hz at a 1-kHz offset and -139dBc/Hz at far-from-carrier offsets. When divided down to GSM's 13MHz, this corresponds to -132dBc/Hz at 1-kHz and -152dBc/Hz at far-from-carrier offsets, both of which satisfy GSM reference oscillator phase noise requirements. This Pierce oscillator achieves such performance using a single disk, not an array, while only consuming 78 microwatts of power, a reduction by a factor of ~4.5 compared with previous work. When power consumption is considered, this performance marks the best figure of merit at 1-kHz carrier offset among published on-chip oscillators to date. Such low phase noise and power consumption posted by a tiny MEMS device may soon become key enablers for low power “set-and-forget” autonomous sensor networks with substantial communication capability.