The effect of elastic anharmonicity on the nonlinear behavior of waveguide-based AlN resonator

This paper presents the effect of elastic anharmonicity in AlN film on the nonlinear performance of extensional AlN resonators. Elastic energy distribution is tailored through dispersion engineering of the waveguide to avoid boundary-induced nonlinearities and enable the study of the elastic anharmonicity contribution on the amplitude-frequency (A-f) characteristic. A 97MHz resonator with a Q of ~2,250 is demonstrated with a linear A-f coefficient of -3.47 ppm/μm
²
and a yield power of 5dBm. Excitation of the device beyond this yield power derives the AlN film into plastic regime and induces a hysteresis in resonator frequency response. A consistent Q over the elastoplastic cycling of the device suggests the dominant contribution of non-structural energy dissipation mechanisms.