A Study of Quality Factor in SAW Resonators for SAW Gyroscope Applications

Abstract

This paper is the first to investigate the quality factor (Q) in surface acoustic wave (SAW) resonators for SAW gyroscopes (SAWG) applications. This constitutes the first analytical and experimental evaluation of SAW loss mechanisms for orthogonal crystal symmetric Y-cut ±45° direction relative to Z-axis on both Lithium Niobate (LN) and Lithium Niobate on Insulator substrate (LNOI). This study demonstrates the ability to minimize the radiation, diffraction, beam steering and bulk scattering loss while exciting the SAW resonators with extremely thick tungsten electrodes (> 2% of acoustic wavelength), which are required to maximize the SAWG sensitivity. This investigation results in SAW devices exhibiting $Q_{total}$ approaching 15,000 and more than 14 × higher than conventional designs. This approach is the first step towards understanding and eliminating the sources of losses in SAWG, enabling the development of a new generation of high-performance MEMS SAW-based gyroscopes with high sensitivity and stability.