A temperature-stable clock using multiple temperature-compensated micro-resonators

In this work, we propose a multi-resonator system capable of achieving a temperature-stable frequency output across a wide temperature range. This system utilizes three temperature-compensated MEMS oscillators whose frequency output undergoes two stages of multiplication and mixing to generate a stable clock signal. In contrast with other circuit compensation techniques, this implementation obviates the need for accurate temperature sensing of the resonator and power hungry ovenization circuits and makes the output stable across the entire calibration range. A system consisting of three temperature-compensated MEMS Pierce oscillators based on AlN-on-silicon ring resonators is implemented and serves as a proof of concept verification for the presented algorithm. A total frequency shift of +/- 8 ppm is seen across the temperature range of -40 °C to +60 °C.