A high-performance oscillator based on RF MEMS resonator and low-noise sustaining circuit for timing applications

Abstract

This paper presents the design and characterization of a micro-electromechanical system (MEMS) oscillator. The oscillator is composed of a low-noise sustaining circuit and a vacuum-encapsulated MEMS disk resonator with excellent frequency response. The sustaining circuit is based on two-port matching networks, a feedback circuit, and a phase shift network. The oscillator exhibits a measured phase noise of -96 dBc/Hz at 1 kHz offset, and -120 dBc/Hz at far-from-carrier offset. Furthermore, the short term and medium term frequency stabilities are ±0.5 ppm and ±5 ppm, respectively. The oscillator shows linear frequency-temperature (f-T) characteristics and small hysteresis. With these promising performances, the proposed MEMS oscillator has potential applications in high-end timing systems.