Frequency Stability of 3D Encapsulated VHF MEMS Resonator

Frequency stability of 3D encapsulated VHF MEMS resonators with Q-factor of 10000 are systematically studied. A negating capacitive compensation technique was developed to eliminating the parasitic effect caused by the PCB circuits. The long-term frequency stability results of the resonance frequency variation and the noise floor of Allan Deviation were ±1 ppm and 26 ppb, respectively, which were comparable to these of the typical quartz resonator. The thermal cycling test between -40 °C and 85 °C for both the long-term operation and the temperature cycling were measured and the results show that the resonant frequency drifts were less than ± 1.5 ppm, indicating the high frequency stability of the encapsulated disk resonator.