一种横向耦合改进型结构极窄带声表面波滤波器研究  

Study on Ultra-Narrow Band Surface Acoustic Wave Filter with Improved Transversely Coupled Structure

作　　者：张显洪[1] 杨卫东 肖强 蒋道军[1] 张晟 施建峰[1] ZHANG Xianhong;YANG Weidong;XIAO Qiang;JIANG Daojun;ZHANG Sheng;SHI Jianfeng(The 26th Institute of China Electronics Technology Group Corporation,Chongqing 400060,China)

机构地区：[1]中国电子科技集团公司第二十六研究所,重庆400060

出　　处：《压电与声光》2024年第3期306-309,共4页Piezoelectrics & Acoustooptics

基　　金：国家重大预研项目(31512030307,31512030304)。

摘　　要：该文采用波导法分析了横向耦合极窄带声表面波滤波器速度变化模式,并用多物理场COMSOL软件对横向耦合声表面波滤波器的中心耦合条结构和耦合距离的变化建模进行计算,并分析频响特性。采用石英晶体作为底衬,设计了频率为898.144 MHz,插入损耗约为6 dB的极窄带声表面波滤波器并进行验证。结果表明,中心耦合条开腔结构的声表面波滤波器的相对带宽达到7.2‰,与不开腔结构5.2‰相对带宽相比,提升了2‰。这说明横向耦合声表面波滤波器的中心耦合条结构变化,能改变极窄带声表面波滤波器的相对带宽。In this study,the velocity change mode of a transversely coupled ultra-narrow band surface acoustic wave filter is analyzed using the waveguide method.The changes in the central coupling strip structure and coupling distance of the transversely coupled surface acoustic wave filter are modeled and calculated using the multi-physics COMSOL software,and the frequency response characteristics are analyzed.An ultra-narrow band SAW filter with frequency of 898.144 MHz and insertion loss of 6 dB has been designed and verified.The results show that the fractional bandwidth of surface acoustic wave filter using the center coupled bar with an open cavity reaches 7.2‰,which is 2‰higher than that of the non-open cavity structure of 5.2‰.This indicates that the change of the center coupled bar structure of a transversely coupled surface acoustic wave filter can change the fractional bandwidth of ultra-narrow band surface acoustic wave filters.

关 键 词：横向耦合 极窄带 声表面波滤波器 物理场COMSOL软件 相对带宽 

分 类 号：TN65[电子电信—电路与系统]