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Yu Z, Guo Y, Fu S, Li B, Liu P, Zhang S, Sun Z. Partially Etched Piezoelectric Film Filled with SiO 2 Structure Applied to A1 Mode Resonators for Transverse Modes Suppression. MICROMACHINES 2023; 14:1745. [PMID: 37763908 PMCID: PMC10537519 DOI: 10.3390/mi14091745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 08/27/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023]
Abstract
With the arrival of the Fifth Generation (5G) communication era, there has been an urgent demand for acoustic filters with a high frequency and ultrawide bandwidth used in radio-frequency (RF) front-ends filtering and signal processing. First-order antisymmetric (A1) lamb mode resonators based on LiNbO3 film have attracted wide attention due to their scalable, high operating frequency and large electromechanical coupling coefficients (K2), making them promising candidates for sub-6 GHz wideband filters. However, A1 mode resonators suffer from the occurrence of transverse modes, which should be addressed to make these devices suitable for applications. In this work, theoretical analysis is performed by finite element method (FEM), and the admittance characteristics of an A1 mode resonator and displacement of transverse modes near the resonant frequency (fr) are investigated. We propose a novel Dielectric-Embedded Piston Mode (DEPM) structure, achieved by partially etching a piezoelectric film filled with SiO2, which can almost suppress the transverse modes between the resonant frequency (fr) and anti-resonant frequency (fa) when applied on ZY-cut LiNbO3-based A1 mode resonators. This indicates that compared with Broadband Piston Mode (BPM), Filled-broadband Piston Mode (FPM) and standard structures, the DEPM structure is superior. Furthermore, the design parameters of the resonator are optimized by adjusting the width, depth and filled materials in the etched window of the DEPM structure to obtain a better suppression of transverse modes. The optimized A1 mode resonator using a DEPM structure exhibits a transverse-free response with a high fr of 3.22 GHz and a large K2 of ~30%, which promotes the application of A1 mode devices for use in 5G RF front-ends.
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Affiliation(s)
- Zhenyi Yu
- School of Internet of Things Engineering, Jiangnan University, Wuxi 214122, China; (Z.Y.); (S.Z.); (Z.S.)
| | - Yu Guo
- School of Internet of Things Engineering, Jiangnan University, Wuxi 214122, China; (Z.Y.); (S.Z.); (Z.S.)
| | - Sulei Fu
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China; (S.F.); (P.L.)
| | - Baichuan Li
- College of Information, Mechanical and Electrical Engineering, Shanghai Normal University, Shanghai 200234, China;
| | - Peisen Liu
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China; (S.F.); (P.L.)
| | - Shuai Zhang
- School of Internet of Things Engineering, Jiangnan University, Wuxi 214122, China; (Z.Y.); (S.Z.); (Z.S.)
| | - Zongqin Sun
- School of Internet of Things Engineering, Jiangnan University, Wuxi 214122, China; (Z.Y.); (S.Z.); (Z.S.)
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Chen Y, Guo Y, Wu R, Wang J, Jing H, Lin J, Tian Y, Zhang H. An analysis of nonlinear thickness vibration frequencies of multi-layered film bulk acoustic resonators. ULTRASONICS 2023; 133:107038. [PMID: 37196574 DOI: 10.1016/j.ultras.2023.107038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 05/01/2023] [Accepted: 05/05/2023] [Indexed: 05/19/2023]
Abstract
The fast reduction of the physical size of film bulk acoustic wave resonators as a layered structure implies the intensification of the electric field which can induce large deformation in the functioning state of devices as a circuit element. Consequently, the nonlinear behavior of the resonator and accompanying properties are to be included and evaluated in the development and optimization for performance improvement. With this objective, the nonlinear formulation of a multilayered film bulk acoustic resonator is presented for the analysis of vibration frequencies and mode shapes with the consideration of larger mechanical deformation. The dominantly linear relationship between the voltage or deformation and frequency is obtained to understand the nonlinear behavior and properties which have been subjected to extensive research analytically and experimentally to satisfy the application needs in all modes of communications and network technology.
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Affiliation(s)
- Yurun Chen
- Piezoelectric Device Laboratory, School of Mechanical Engineering & Mechanics, 818 Fenghua Road, Ningbo 315211, Zhejiang, China
| | - Yan Guo
- Piezoelectric Device Laboratory, School of Mechanical Engineering & Mechanics, 818 Fenghua Road, Ningbo 315211, Zhejiang, China; College of Science and Technology, Ningbo University, 521 Wenwei Road, Cixi 315300, Zhejiang, China
| | - Rongxing Wu
- Piezoelectric Device Laboratory, School of Mechanical Engineering & Mechanics, 818 Fenghua Road, Ningbo 315211, Zhejiang, China; Department of Architectural Engineering, Ningbo Polytechnic, 388 East Lushan Road, Ningbo 315800, Zhejiang, China
| | - Ji Wang
- Piezoelectric Device Laboratory, School of Mechanical Engineering & Mechanics, 818 Fenghua Road, Ningbo 315211, Zhejiang, China; Pexar Technology Corporation, Institute of Acoustics Technology, 5 Yanjiuyuan Road, Changshu Suzhou 215513, Jiangsu, China.
| | - Huimin Jing
- Piezoelectric Device Laboratory, School of Mechanical Engineering & Mechanics, 818 Fenghua Road, Ningbo 315211, Zhejiang, China
| | - Ji Lin
- Piezoelectric Device Laboratory, School of Mechanical Engineering & Mechanics, 818 Fenghua Road, Ningbo 315211, Zhejiang, China
| | - Yahui Tian
- Institute of Acoustics, Chinese Academy of Sciences, 100190 Beijing, China
| | - Haifeng Zhang
- Department of Mechanical and Energy Engineering, University of North Texas, Denton, TX 76203, USA
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Development and Application of SAW Filter. MICROMACHINES 2022; 13:mi13050656. [PMID: 35630123 PMCID: PMC9145957 DOI: 10.3390/mi13050656] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 03/26/2022] [Accepted: 03/27/2022] [Indexed: 12/10/2022]
Abstract
With the in-depth advancement of the fifth generation (5G) mobile communication technology, the technical requirements for filters are also constantly improving. Surface acoustic wave (SAW) filters are widely used in home TV, mobile communications, radio frequency filters and radar due to their simple structure, few mask layers, easy miniaturization, and low cost. Through the continuous improvement of communication technology, SAW has developed into various high-performance acoustic filters from bulk SAW with the support of some new architectures, new materials and advanced modeling techniques. This paper analyzes and reviews the research situation of SAW filter technology.
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Lu Z, Fu S, Xu Z, Wang W, Zhang Q, Zhang J, Zhang H. Fractional Bandwidth up to 24% and Spurious Free SAW Filters on Bulk 15°YX-LiNbO3 Substrates Using Thickness-Modulated IDT Structures. MICROMACHINES 2022; 13:mi13030439. [PMID: 35334731 PMCID: PMC8950525 DOI: 10.3390/mi13030439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/09/2022] [Accepted: 03/11/2022] [Indexed: 11/16/2022]
Abstract
To cope with ubiquitous wireless connectivity and the increased and faster data delivery in 5G communication, surface acoustic wave (SAW) filters are progressively requiring wider bandwidths. Conventional bulk 15°YX-LiNbO3 substrates with a large coupling coefficient (K2) are attractive for the low-cost mass production of wideband SAW filters, but these generally suffer from spurious responses, limiting their practical application. In this work, a novel and simple SAW configuration is proposed that uses thickness-modulated interdigital transducer (IDT) structures to overcome the limitations set by spurious responses. Different from the conventional design where the thicknesses of the IDT electrodes in the series and parallel resonators generally kept the same, the proposed configuration adopts IDT electrodes of different thicknesses in the series and shunt resonators to suppress or remove unwanted spurious Rayleigh modes from the filter passband. Two different ultra-wideband SAW filter designs employing thickness-modulated IDTs were designed and fabricated to validate the effective suppression of spurious modes. The SAW filters experimentally featured spurious-free responses in the passband as well as a large 3 dB fractional bandwidth (FBW) in the 18.0% and 24.1% ranges and low insertion losses below 1 dB. This work can significantly broaden the range of applications for SAW devices and can open a pathway to commercialize ultra-wideband SAW filters in 5G communication systems.
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Affiliation(s)
- Zengtian Lu
- School of Mechanical Engineering, Southeast University, Nanjing 211189, China; (Z.L.); (Z.X.); (J.Z.)
| | - Sulei Fu
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
- Correspondence: (S.F.); (H.Z.); Tel.: +86-025-52090511 (H.Z.)
| | - Zhibin Xu
- School of Mechanical Engineering, Southeast University, Nanjing 211189, China; (Z.L.); (Z.X.); (J.Z.)
| | - Weibiao Wang
- Shoulder Electronics Limited, Wuxi 214124, China;
| | - Qiaozhen Zhang
- College of Information, Mechanical and Electrical Engineering, Shanghai Normal University, Shanghai 200234, China;
| | - Jianrun Zhang
- School of Mechanical Engineering, Southeast University, Nanjing 211189, China; (Z.L.); (Z.X.); (J.Z.)
| | - Hui Zhang
- School of Mechanical Engineering, Southeast University, Nanjing 211189, China; (Z.L.); (Z.X.); (J.Z.)
- Correspondence: (S.F.); (H.Z.); Tel.: +86-025-52090511 (H.Z.)
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