电磁寄生参数对SAW滤波器性能的影响  

Influence of Electromagnetic Parasitic Parameters on the Performance of SAW Filters

作　　者：魏园林 帅垚[2,3] 魏子杰[3] 吴传贵[2,3] 罗文博[2,3] 张万里[2,3] WEI Yuanlin;SHUAI Yao;WEI Zijie;WU Chuangui;LUO Wenbo;ZHANG Wanli(College of Optoelectronic Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China;Chongqing Institute of Microelectronics Industry Technology,University of Electronic Science and Technology of China,Chongqing 401332,China;School of Electronic Science and Engineering,University of Electronic Science and Technology of China,Chengdu 611731,China)

机构地区：[1]重庆邮电大学光电工程学院,重庆400065 [2]电子科技大学重庆微电子产业技术研究院,重庆401332 [3]电子科技大学集成电路科学与工程学院,四川成都611731

出　　处：《压电与声光》2024年第4期463-467,共5页Piezoelectrics & Acoustooptics

基　　金：四川省科技计划基金资助项目(2020YFJ0002)。

摘　　要：设计了B41频段的声表面波(SAW)滤波器,利用三维电磁场仿真工具HFSS建立表面贴装器件(SMD)封装和芯片级(CSP)封装模型,对比两种封装的声-电磁联合仿真结果得出,在滤波器电路拓扑结构中,当2条不同并联支路连接在一起时,由于SMD封装键合引线的电磁寄生参数影响,滤波器在高频处的带外抑制会出现“上翘”。建立不同键合线数量、直径及长度的SMD封装模型,并仿真计算S参数。对比仿真结果可知,随着键合线直径的增大和长度的减小,其等效电感逐渐变小,即键合线的电磁寄生参数逐渐减小,对SAW滤波器性能的影响逐渐减弱,高频处的带外抑制性能得到优化。结果表明,CSP封装植球倒扣的电磁寄生参数更小,声-电磁联合仿真的结果更优,与实测结果吻合较好。In this study,a B41 band SAW filter was designed,and SMD and CSP packages were modeled using 3D electromagnetic field simulation software.The acoustic-electromagnetic simulation results of the two packages were compared,leading to the preliminary conclusion that,for the topology of the filter circuit,the out-of-band rejection at high frequencies may increase(warping “upward”) when two different parallel branches are connected.This effect is due to the electromagnetic parasitic parameters of the bonding leads in the SMD package.SMD package models were established and simulated with varying numbers,diameters,and lengths of bonding wires to calculate the S-parameters.The simulation results indicate that as the diameter of the bonding wire increases and the length decreases,its equivalent inductance becomes smaller.Consequently,the electromagnetic parasitic parameters of the bonding wire decrease,reducing their influence on the performance of the SAW filter,and optimizing the out-of-band rejection performance at high frequencies.Additionally,the ball-implanted inverted button of the CSP package exhibits smaller electromagnetic parasitic parameters,resulting in better joint acoustic-electromagnetic simulation outcomes,which align well with the measured results.

关 键 词：SAW滤波器 表面贴装器件(SMD)封装 芯片级(CSP)封装 电磁寄生参数 带外抑制 键合线 

分 类 号：TN384[电子电信—物理电子学] TN65