Thermoelastic damping suppression method of micro-beam resonators with basically constant resonant frequency

Abstract

High-Q micro-beam resonators have been widely applied in communication fields such as narrowband filters, but thermoelastic damping restricts the further improvement of quality factor. Traditional method such as overall size optimization used for thermoelastic quality factor (Q TED) improvement will cause the resonant frequency of the resonator change greatly, which will not be allowed in narrowband filters. In this article, three slots are introduced into a beam resonator to greatly reduce the thermoelastic damping by rationally arranging the length ratio of the central slot and the side slot, while the resonant frequency is basically kept unchanged. The feasibility is verified by parametric finite element simulation method. The results indicate that without changing the overall size of the micro-beam resonator, the resonant frequency remains unchanged and the Q TED of the resonator can be doubled over twice both in the isothermal region and adiabatic region by placing side slots of 10% and a central slot of 30%. The proposed thermoelastic damping suppression method shows potential applicability for MEMS resonators in high-order mode of vibration.