Experimental Study of Transverse Mode Suppression on Wideband Hetero Acoustic Layer Surface Acoustic Wave Resonator

• Published in: IEEE transactions on ultrasonics, ferroelectrics, and frequency control Vol. 71; no. 2; p. 1
• Main Authors: Guo, Yong, Kadota, Michio, Tanaka, Shuji
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.02.2024; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Air gaps; Apodization; Broadband; Dummy Electrode; Electrodes; Frequency control; LiNbO<sub xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">3; Lithium niobates; Narrowband; Optical resonators; Q-factor; Quality Factor; Resonators; Shape; Surface acoustic wave devices; Surface Acoustic Wave Resonator; Transverse mode; Wideband; Zigzag Apodization
• ISSN: 0885-3010; 1525-8955; 1525-8955
• DOI: 10.1109/TUFFC.2023.3347509

Transverse mode suppression is a great challenge for high performance surface acoustic wave (SAW) resonators. Conventional methods work well on narrow band resonators, but their performances on wideband resonator have not been demonstrated. In this paper, we give an in-depth study on the transverse mode suppression of wideband resonators using 11°YX-LiNbO 3 (LN)/ 70°Y90°X-Quartz (Qz) hetero acoustic layer structure as a platform. Two groups of design, including new dummy electrode and zigzag shape apodization, are proposed. The measured results show that the shape of the dummy electrode is not the dominant factor to affect the transverse mode. The proposed zigzag shape apodization can effectively suppress the transverse, at the same time maintain the Quality (Q) factor at the same level with normal type. Additionally, stronger suppression ability can be realized with tiny trade-off of Q factor.