A Laterally Excited Bulk Acoustic Wave Resonator Based on LiNbO<sub>3</sub> with Arc-Shaped Electrodes

High frequency and large bandwidth are growing trends in communication radio-frequency devices. The LiNbO<sub>3</sub> thin film material is expected to become the preferred piezoelectric material for high coupling resonators in the 5G frequency band due to its ultra-high piezoelectric co...

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Main Authors: Jieyu Liu, Wenjuan Liu, Zhiwei Wen, Min Zeng, Chengliang Sun
Format: Article
Language:English
Published: MDPI AG 2024-11-01
Series:Micromachines
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Online Access:https://www.mdpi.com/2072-666X/15/11/1367
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author Jieyu Liu
Wenjuan Liu
Zhiwei Wen
Min Zeng
Chengliang Sun
author_facet Jieyu Liu
Wenjuan Liu
Zhiwei Wen
Min Zeng
Chengliang Sun
author_sort Jieyu Liu
collection DOAJ
description High frequency and large bandwidth are growing trends in communication radio-frequency devices. The LiNbO<sub>3</sub> thin film material is expected to become the preferred piezoelectric material for high coupling resonators in the 5G frequency band due to its ultra-high piezoelectric coefficient and low loss characteristics. The main mode of laterally excited bulk acoustic wave resonators (XBAR) have an ultra-high sound velocity, which enables high-frequency applications. However, the interference of spurious modes is one of the main reasons hindering the widespread application of XBAR. In this paper, a Z-cut LiNbO<sub>3</sub> thin film-based XBAR with arc-shaped electrodes is presented. We investigate the electric field distribution of the XBAR, while the irregular boundary of the arc-shaped electrodes affects the electric field between the existing interdigital transducers (IDTs). The mode shapes and impedance response of the XBAR with arc-shaped electrodes and the XBARs with traditional IDTs are compared in this work. The fabricated XBAR on a 350 nm Z-cut LiNbO<sub>3</sub> thin film with arc-shaped electrodes operating at over 5 GHz achieves a high effective electromechanical coupling coefficient of 29.8% and the spurious modes are well suppressed. This work promotes an XBAR with an optimized electrode design to further achieve the desired performance.
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institution Kabale University
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language English
publishDate 2024-11-01
publisher MDPI AG
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series Micromachines
spelling doaj-art-431da56a57b24cf7bebd6f2b113336a52024-11-26T18:13:59ZengMDPI AGMicromachines2072-666X2024-11-011511136710.3390/mi15111367A Laterally Excited Bulk Acoustic Wave Resonator Based on LiNbO<sub>3</sub> with Arc-Shaped ElectrodesJieyu Liu0Wenjuan Liu1Zhiwei Wen2Min Zeng3Chengliang Sun4The Institute of Technological Sciences, Wuhan University, Wuhan 430072, ChinaThe Institute of Technological Sciences, Wuhan University, Wuhan 430072, ChinaThe Institute of Technological Sciences, Wuhan University, Wuhan 430072, ChinaThe Institute of Technological Sciences, Wuhan University, Wuhan 430072, ChinaThe Institute of Technological Sciences, Wuhan University, Wuhan 430072, ChinaHigh frequency and large bandwidth are growing trends in communication radio-frequency devices. The LiNbO<sub>3</sub> thin film material is expected to become the preferred piezoelectric material for high coupling resonators in the 5G frequency band due to its ultra-high piezoelectric coefficient and low loss characteristics. The main mode of laterally excited bulk acoustic wave resonators (XBAR) have an ultra-high sound velocity, which enables high-frequency applications. However, the interference of spurious modes is one of the main reasons hindering the widespread application of XBAR. In this paper, a Z-cut LiNbO<sub>3</sub> thin film-based XBAR with arc-shaped electrodes is presented. We investigate the electric field distribution of the XBAR, while the irregular boundary of the arc-shaped electrodes affects the electric field between the existing interdigital transducers (IDTs). The mode shapes and impedance response of the XBAR with arc-shaped electrodes and the XBARs with traditional IDTs are compared in this work. The fabricated XBAR on a 350 nm Z-cut LiNbO<sub>3</sub> thin film with arc-shaped electrodes operating at over 5 GHz achieves a high effective electromechanical coupling coefficient of 29.8% and the spurious modes are well suppressed. This work promotes an XBAR with an optimized electrode design to further achieve the desired performance.https://www.mdpi.com/2072-666X/15/11/1367XBARarc-shaped electrodeelectromechanical coupling coefficientspurious modes
spellingShingle Jieyu Liu
Wenjuan Liu
Zhiwei Wen
Min Zeng
Chengliang Sun
A Laterally Excited Bulk Acoustic Wave Resonator Based on LiNbO<sub>3</sub> with Arc-Shaped Electrodes
Micromachines
XBAR
arc-shaped electrode
electromechanical coupling coefficient
spurious modes
title A Laterally Excited Bulk Acoustic Wave Resonator Based on LiNbO<sub>3</sub> with Arc-Shaped Electrodes
title_full A Laterally Excited Bulk Acoustic Wave Resonator Based on LiNbO<sub>3</sub> with Arc-Shaped Electrodes
title_fullStr A Laterally Excited Bulk Acoustic Wave Resonator Based on LiNbO<sub>3</sub> with Arc-Shaped Electrodes
title_full_unstemmed A Laterally Excited Bulk Acoustic Wave Resonator Based on LiNbO<sub>3</sub> with Arc-Shaped Electrodes
title_short A Laterally Excited Bulk Acoustic Wave Resonator Based on LiNbO<sub>3</sub> with Arc-Shaped Electrodes
title_sort laterally excited bulk acoustic wave resonator based on linbo sub 3 sub with arc shaped electrodes
topic XBAR
arc-shaped electrode
electromechanical coupling coefficient
spurious modes
url https://www.mdpi.com/2072-666X/15/11/1367
work_keys_str_mv AT jieyuliu alaterallyexcitedbulkacousticwaveresonatorbasedonlinbosub3subwitharcshapedelectrodes
AT wenjuanliu alaterallyexcitedbulkacousticwaveresonatorbasedonlinbosub3subwitharcshapedelectrodes
AT zhiweiwen alaterallyexcitedbulkacousticwaveresonatorbasedonlinbosub3subwitharcshapedelectrodes
AT minzeng alaterallyexcitedbulkacousticwaveresonatorbasedonlinbosub3subwitharcshapedelectrodes
AT chengliangsun alaterallyexcitedbulkacousticwaveresonatorbasedonlinbosub3subwitharcshapedelectrodes
AT jieyuliu laterallyexcitedbulkacousticwaveresonatorbasedonlinbosub3subwitharcshapedelectrodes
AT wenjuanliu laterallyexcitedbulkacousticwaveresonatorbasedonlinbosub3subwitharcshapedelectrodes
AT zhiweiwen laterallyexcitedbulkacousticwaveresonatorbasedonlinbosub3subwitharcshapedelectrodes
AT minzeng laterallyexcitedbulkacousticwaveresonatorbasedonlinbosub3subwitharcshapedelectrodes
AT chengliangsun laterallyexcitedbulkacousticwaveresonatorbasedonlinbosub3subwitharcshapedelectrodes