Frequency comb in 1:3 internal resonance of coupled micromechanical resonators

Frequency comb in microelectromechanical systems has attracted many concerns, which is expected to realize great achievements analogous with the optical frequency comb. Previous frequency combs are generated by mode coupling in a single micro-resonator. To pursuit more excellent tunability and robustness, it is impending to create a frequency comb through another way, i.e., coupled but relatively independent micro-resonators. In this work, a frequency comb in 1:3 internal resonance region of an electrostatically coupled microsystem is reported. We demonstrate the occurrence conditions and its influencing factors of the frequency comb. A dynamical explanation, which has good agreement with the experimental results, is presented to further reveal its intrinsic mechanism. Our finding provides a controllable method to produce a frequency comb that is beneficial to potential applications, such as signal processing and sensing sensitivity enhancement.