With the rapid progress of the wireless communication technique and the fast growing of the radio frequency (RF) markets, the development of wideband surface acoustic wave (SAW) filter is intensely pursued in RF front-end platforms. In this study, a novel configuration of SAW device was proposed in 15°YX-LiNbO₃ (300 ​nm)/SiO₂ (600 ​nm)/Si heterostructure, where the series and shunt resonator innovatively adopt Cu electrodes of different thickness to suppress the unwanted Rayleigh mode efficiently. Series and shunt resonators with clean spectrum and high electromechanical coupling coefficients over 20% were experimentally achieved under the guidance of finite element method calculation. Based on the resonator results, a ladder-type SAW filter with a very large 3-dB fractional bandwidth near 30% was successfully designed and fabricated. The minimum insertion loss of device is as small as 1.1 ​dB while the in-band fluctuation is less than 0.3 ​dB. The unprecedented wideband property of SAW device indicates that the proposed configuration is expected to become one of the solutions of wideband filter in fifth-generation mobile communication, and possess great commercial application prospects.

随着无线通信技术的快速进步和射频（RF）市场的快速增长，宽带表面声波（SAW）滤波器的开发在射频前端平台上得到了强烈的关注。在这项研究中，在 15°YX-LiNbO ₃ (300 nm)/SiO _{2 中}提出了一种新的 SAW 器件配置(600 nm)/Si 异质结构，其中串联和并联谐振器创新地采用不同厚度的 Cu 电极，以有效抑制不需要的瑞利模式。在有限元法计算的指导下，通过实验实现了频谱清晰、机电耦合系数超过20%的串联和并联谐振器。基于谐振器的结果，成功地设计和制造了一个具有接近 30% 的非常大的 3-dB 分数带宽的梯形 SAW 滤波器。器件最小插入损耗小至1.1dB，带内波动小于0.3dB。SAW器件前所未有的宽带特性表明，所提出的配置有望成为第五代移动通信宽带滤波器的解决方案之一，