Zou Jie, Yantchev Ventsislav, Iliev Filip, Plessky Victor, Samadian Sohrab, Hammond Robert B, Turner Patrick J
IEEE Trans Ultrason Ferroelectr Freq Control. 2020 Feb;67(2):374-386. doi: 10.1109/TUFFC.2019.2944302. Epub 2019 Sep 27.
This study lays a foundation for the design of the SH plate acoustic wave (PAW) resonators based on LiNbO plate, and are applicable to the ultra-wideband filters and next-generation tunable filters. The coupling coefficient ( k ) of SH mode is optimized to as high as 55% and wideband spurious are well controlled by analyzing the propagation characteristics of plate modes in LiNbO. The SH mode is demonstrated to be slowly dispersive and features the superiority of interdigital transducer (IDT)-defining frequency over most other plate modes. On the device level, the transducer types and electrode materials are investigated and compared. In addition, for edge-reflected SH resonators, stopband dispersion analysis is provided and the longitudinal ripples are suppressed. For edge-reflected SH resonators, a novel perfect edge reflector is proposed with elimination of longitudinal spurious ripples.
本研究为基于铌酸锂（LiNbO）板的横向剪切（SH）模式声波（PAW）谐振器的设计奠定了基础，适用于超宽带滤波器和下一代可调滤波器。通过分析铌酸锂中板模式的传播特性，将SH模式的耦合系数（k）优化至高达55%，并很好地控制了宽带杂散。结果表明，SH模式具有缓慢的色散特性，与大多数其他板模式相比，在定义叉指换能器（IDT）频率方面具有优势。在器件层面，对换能器类型和电极材料进行了研究和比较。此外，对于边缘反射式SH谐振器，进行了阻带色散分析并抑制了纵向纹波。对于边缘反射式SH谐振器，提出了一种新型的完美边缘反射器，可消除纵向杂散纹波。
