1/f noise in surface acoustic wave (SAW) resonators

Flicker noise measurements on 40 additional two-port ion etched groove SAW resonators (giving a total of 56 devices) have confirmed that resonators with large active acoustic areas exhibit lower 1/f noise levels than smaller devices. The observed noise levels vary inversely with the size of the SAW resonator. It has also been observed that there are no large differences in the 1/f noise levels of devices fabricated on either different grades of quartz or on swept and unswept material. Previous estimates of the active acoustic area (or volume) of a SAW resonator were based on the dimensions of rectangular acoustic energy profiles that had the same peak energy density and the same total energy as the actual resonator. More precise calculations of device acoustic volume are presented herein using perturbation theory to correctly handle the non-uniform acoustic energy distributions in a SAW resonator