Li Menghui, Qi Mengke, Chen Yuanhang, Cheng Yimin, Cao Liang, Mu Xiaojing
The Key Laboratory of Optoelectronic Technology and Systems of Ministry of Education, Chongqing University, Chongqing 400044, China.
The International Research and Development Center of Micro-Nano Systems and New Materials Technology, Chongqing University, Chongqing 400044, China.
ACS Appl Mater Interfaces. 2024 Sep 4;16(35):46872-46878. doi: 10.1021/acsami.4c07223. Epub 2024 Aug 22.
With the rapid development of mobile communication technology, the POI (piezoelectric on insulator) structure has gained recognition in the field of RF filtering. However, transverse modes remain in the passband of corresponding surface acoustic wave (SAW) devices, which impedes their application in crowded spectra. This article introduces a groove configuration to suppress transverse modes for POI SAW resonators employing a 50°YX-LiTaO/SiO/Si multilayered structure. First, the response of conventional POI SAW resonators was calculated by the 3D periodic FEM method, and the results indicate that transverse modes caused by energy leakage to busbar regions are serious in POI SAW resonators. Then, the groove configuration was adopted to confine energy within the aperture region by reducing the velocity at the end of IDT electrodes, and the groove dimension was optimized to achieve a nearly spurious-free response in the passband. Finally, experimental results of fabricated one-port SAW resonators with optimal groove configuration were provided to validate the suppression of transverse modes and the enhancement of the factor in the POI SAW resonator.
随着移动通信技术的快速发展，POI（绝缘体上压电）结构在射频滤波领域获得了认可。然而，横向模式存在于相应的表面声波（SAW）器件的通带中，这阻碍了它们在拥挤频谱中的应用。本文介绍了一种用于采用50°YX-LiTaO/SiO/Si多层结构的POI SAW谐振器的凹槽结构，以抑制横向模式。首先，通过三维周期性有限元方法计算了传统POI SAW谐振器的响应，结果表明在POI SAW谐振器中，能量泄漏到母线区域所导致的横向模式很严重。然后，采用凹槽结构通过降低叉指换能器（IDT）电极末端的速度将能量限制在孔径区域内，并对凹槽尺寸进行了优化，以在通带中实现几乎无杂散的响应。最后，提供了具有最佳凹槽结构的制成的单端口SAW谐振器的实验结果，以验证POI SAW谐振器中横向模式的抑制以及品质因数的提高。
