High Electromechanical Coupling Coefficient of Longitudinally Excited Shear Wave Resonator Based on Optimized Bragg Structure
Zhiheng Zhang,
Weipeng Xuan,
Hong Jiang,
Weilun Xie,
Zhaoling Li,
Shurong Dong,
Hao Jin,
Jikui Luo
Affiliations
Zhiheng Zhang
Ministry of Education Key Laboratory of RF Circuits and Systems, College of Electronics & Information, Hangzhou Dianzi University, Hangzhou 310005, China
Weipeng Xuan
Ministry of Education Key Laboratory of RF Circuits and Systems, College of Electronics & Information, Hangzhou Dianzi University, Hangzhou 310005, China
Hong Jiang
Ministry of Education Key Laboratory of RF Circuits and Systems, College of Electronics & Information, Hangzhou Dianzi University, Hangzhou 310005, China
Weilun Xie
Ministry of Education Key Laboratory of RF Circuits and Systems, College of Electronics & Information, Hangzhou Dianzi University, Hangzhou 310005, China
Zhaoling Li
Ministry of Education Key Laboratory of RF Circuits and Systems, College of Electronics & Information, Hangzhou Dianzi University, Hangzhou 310005, China
Shurong Dong
Key Laboratory of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, College of Information Science & Electronic Engineering, Zhejiang University, Hangzhou 310027, China
Hao Jin
Key Laboratory of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, College of Information Science & Electronic Engineering, Zhejiang University, Hangzhou 310027, China
Jikui Luo
Ministry of Education Key Laboratory of RF Circuits and Systems, College of Electronics & Information, Hangzhou Dianzi University, Hangzhou 310005, China
In this work, a longitudinally excited shear-wave resonator (YBAR) based on single-crystalline lithium tantalate (LiTaO3, LT) thin film is proposed. The YBAR has a 200 nm X-cut thin film and molybdenum electrode. A high effective electromechanical coupling coefficient (k2eff) of up to 19% for the suspension-type structure was obtained. Furthermore, a Bragg reflector (SiO2/Pt) with optimized layer thickness ratio was employed to improve the performance of the YBAR. Compared to the acoustic wave resonators with the conventional quarter-wave (λ/4) Bragg reflector, the proposed YBAR with an optimized Bragg reflector can reflect both the longitudinal and shear waves efficiently, and resonators with spurious-free response and high quality (Q) value were achieved. This work provides a potential solution to enabling high coupling micro-acoustic resonators with high Q factor in the 5G/6G communication system.
