Studying the Influence of Temperature on the Operation of a Resonator of a Frequency Micromechanical Accelerometer

Abstract

A micromechanical accelerometer (MMA) is used to measure the acceleration based on the change in frequency of the resonator when the acceleration is caused by the displacement of the inertial mass. Its sensitivity can be influenced by factors such as vibration noise and temperature. In this study, using the calculation and modeling in the ANSYS program, the influence of the temperature on the natural oscillation frequency of resonators of various designs has been studied. It is shown that in a number of the studied designs of frequency MMA resonators, the frequency change ∆f₀ caused by an increase in temperature is comparable and even exceeds the change in the frequency due to the acceleration effect. It is shown that the known designs of resonators whose operation is based on the oscillations of a beam fixed at both ends do not ensure the stability of oscillations at their natural frequency with a change in temperature. For resonators based on the oscillations of a cantilever beam, the frequency barely changes due to the increase in temperature. The best result from the point of view of the temperature’s stability is obtained for a resonator in the form of a cantilever beam with the beam resonator inside it, for which the frequency change ∆f₀ with the temperature increasing up to 70°C was only 4 Hz. The study of the basic MMA construction, consisting of an inertial mass with a resonator made in the form of a cantilever beam with a resonator inside shows that the natural oscillation frequency of this construction is stable when the temperature increases up to 70°C. In this case, the sensitivity is 130 Hz/g and does not depend on temperature.