Enhanced Frequency Stability in a Blue-Sideband Excited Mems Resonator with Phononic-Frequency-Combs-Like Behaviour

For the first time, this work reports an intriguing phononic-frequency-combs (PFCs)-like behavior within a double-ended-tuning-fork (DETF) MEMS resonator, when excited using a recent emerging blue-sideband excitation (BSE) scheme. Further investigations were conducted beyond the PFC-like spectrum response. Notably, the spacing of the comb remains largely unaffected by changes in the excitation amplitude. Introducing variations in a DC offset voltage as surrogate stiffness perturbations, the two primary spectral line frequencies among the PFCs exhibit contrasting and nearly offsetting sensitivity to these perturbations. Built upon this finding, experimental results show 15-fold frequency noise reduction and 13-fold stability enhancement, suggesting that the novel phenomenon is of considerable potential for highly stable MEMS oscillators.