Characteristics of ZnO/diamond/Si SAW resonators

The surface acoustic wave (SAW) resonator response of ZnO/diamond/Si layered structures are calculated and discussed including velocity dispersion. Smith´s second equivalent circuit including energy storage effects is used to calculate the resonator response. The effect of velocity dispersion appears for the shift of resonant frequency to the expected center frequency, and appears for the bandwidth of resonator becoming narrower than that of the nondispersive case. The coupling of modes equation is modified for the velocity dispersion to explain these effects. The reflection coefficients of gratings are calculated for velocity dispersive case and the non velocity dispersive case. These results agree with the response calculated by the equivalent circuit model. Assuming the deviation of velocity dispersion is small neighboring the resonance area, the effect of velocity dispersion is explained theoretically. The ZnO/diamond/Si SAW resonators provide high frequency operation and high quality factor (Q) SAW resonators due to the velocity dispersion