Through-Holes Design for Ideal LiNbO3 A1 Resonators

Shu-Mao Wu; Chen-Bei Hao; Zhen-Hui Qin; Yong Wang; Hua-Yang Chen; Si-Yuan Yu; Yan-Feng Chen

doi:10.3390/mi14071341

Through-Holes Design for Ideal LiNbO₃ A1 Resonators

Micromachines (Basel). 2023 Jun 30;14(7):1341. doi: 10.3390/mi14071341.

Authors

Shu-Mao Wu¹, Chen-Bei Hao¹, Zhen-Hui Qin¹, Yong Wang², Hua-Yang Chen¹, Si-Yuan Yu¹, Yan-Feng Chen¹

Affiliations

¹ National Laboratory of Solid State Microstructures, Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China.
² State Key Lab of Crystal Materials, Shandong University, Jinan 250100, China.

Abstract

This paper proposes a method to realize ideal lithium niobate (LiNbO₃) A1 resonators. By introducing subwavelength through-holes between the interdigital transducer (IDT) electrodes on the LiNbO₃ surface, all unfavorable spurious modes of the resonators can be suppressed completely. It is convenient and valid for various IDT electrode parameters and different LiNbO₃ thicknesses. Also, this method does not require additional device fabrication steps. At the same time, these through-holes can greatly reduce the suspended area of the LiNbO₃ thin film, thus significantly improving the design flexibility, compactness, mechanical stability, temperature stability, and power tolerance of the resonators (and subsequent filters). It is expected to become an important means to promote the practical application of LiNbO₃ A1 filters and even all Lamb waves filters.

Keywords: Lamb wave resonators/filters; LiNbO3 thin films; XBARs; wireless communications.

Abstract

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