论文标题
Linbo $ _3 $/蓝宝石基板上的高速速度声波，用于低6-GHz设备
A Very-High-Velocity Acoustic Wave on a LiNbO$_3$/Sapphire Substrate for Use in Sub-6-GHz Devices
论文作者
论文摘要
This letter presents a numerical investigation of acoustic modes propagating in an LiNbO$_3$/sapphire substrate under a periodic Al grating, demonstrating the occurrence of longitudinal leaky SAWs (LLSAWs) with a unique combination of very high velocities exceeding 10 000 m/s, an electromechanical coupling coefficients of 4.5%, and negligible leakage into the substrate.通过优化Linbo $ _3 $（LN）板和Al电极厚度来抑制泄漏。与常规的锯底物相比，LN/蓝宝石底物为周期性电极结构提供2至2.5倍的频率，并通过标准的光刻过程实现了6-GHz设备的生产。此外，所需的LN板和Al电极厚度与现有的晶圆粘合技术保持兼容。对谐振器中LLSAW分散体的分析表明，波浪的表现是完美的雷利（Releigh）所见，这不受与虚假模式相互作用的影响。发现的最佳LN/蓝宝石基材是在低6-GHz频谱中运行的高性能锯设备的理想候选者。
This letter presents a numerical investigation of acoustic modes propagating in an LiNbO$_3$/sapphire substrate under a periodic Al grating, demonstrating the occurrence of longitudinal leaky SAWs (LLSAWs) with a unique combination of very high velocities exceeding 10 000 m/s, an electromechanical coupling coefficients of 4.5%, and negligible leakage into the substrate. The leakage was suppressed by optimizing the LiNbO$_3$ (LN) plate and Al electrode thickness. Compared with conventional SAW substrates, the LN/sapphire substrate offers 2- to 2.5-fold higher frequencies for periodic electrode structures and enables the production of 6-GHz devices by standard photolithographic processes. Moreover, the required LN plate and Al electrode thicknesses remain compatible with existing wafer bonding technologies. An analysis of LLSAW dispersion in a resonator reveals that the wave behaves as a perfect Rayleigh SAW unperturbed by interactions with spurious modes. The found optimal LN/sapphire substrates are perfect candidates for high-performance SAW devices operating in the sub-6-GHz spectrum.
