具有单相单向换能器的水平剪切声表面波压力传感器插入损耗特性  

The insertion loss of shear horizontal surface acoustic wave pressure sensor with single-phase unidirectional transducer

作　　者：杨健 李媛媛[1] 江蓓 季雪咪 YANG Jian;LI Yuanyuan;JIANG Bei;JI Xuemi(School of Electrical and Electronic Engineering,Shanghai University of Engineering Science,Shanghai 201620)

机构地区：[1]上海工程技术大学电子电气工程学院,上海201620

出　　处：《声学学报》2021年第5期749-758,共10页Acta Acustica

基　　金：国家自然科学基金青年科学基金项目(61703269)资助。

摘　　要：为实现水平剪切声表面波压力传感器低损耗设计,系统研究了均匀叉指换能器(IDT)和单相单向换能器(SPUDT)器件的声波能量损耗性能。在确定最优反射系数的SPUDT结构的基础上,建立3D周期性有限元仿真模型,计算器件表面振动位移和双向输出电压瞬态响应。通过对电压信号进行傅里叶变换获得器件模型的插入损耗,并制备两种不同换能器的声学传感器,测试其频率特性和灵敏度。与均匀IDT相比,基于SPUDT器件插入损耗的仿真和实验结果分别降低了5.2 dB和5.6 dB,SPUDT器件灵敏度约为均匀IDT器件的两倍。结果表明,SPUDT能有效降低SH-SAW压力传感器声波能量的单向损耗,提高检测灵敏度,且构建的3D周期性有限元仿真模型有助于声学传感器的声波损耗分析,实现高精度和小型化的声学测量系统。In order to realize the low loss design of shear horizontal surface acoustic wave pressure sensor,the acoustic wave energy loss performance of the sensor with InterDigital Transducer(IDT)and Single-Phase UniDirectional Transducer(SPUDT)is systemically studied.Through the establishment of a 3D periodic finite element simulation model with the SPUDT with the optimal reflection coefficient,the device surface vibration displacement and output voltage time response are calculated.By transforming the voltage signal using Fourier Transform,the insertion loss of the sensor model is obtained.Two different acoustic devices were prepared and their frequency characteristics and sensitivity were tested as well.Compared with uniform IDT,the insertion loss of sensor with SPUDT is reduced by 5.2 dB and 5.6 dB in simulation and experiment,and sensitivity of the sensor with SPUDT is about twice that of the sensor with uniform IDT.The results show that SPUDT,as transducer of shear horizontal surface acoustic wave pressure sensor,can effectively reduce the energy loss of acoustic wave and improve the detection sensitivity.In addition,the construction of the 3D periodic finite element simulation model is beneficial to the acoustic wave loss analysis of acoustic measuring devices and the realization of a high-precision and miniaturized acoustic measurement system.

关 键 词：SAW压力传感器 声学传感器 插入损耗 傅里叶变换 器件模型 声波能量 损耗分析 瞬态响应 

分 类 号：TB51[理学—物理] TP212[理学—声学]