基于电学拓扑结构拓展FBAR滤波器带宽研究  

Study on Expanding Bandwidth of FBAR Filter Based on Electrical Topology

作　　者：常亚慧 汪为民 CHANG Yahui;WANG Weimin(Key Laboratory of Optoelectronic Technology and Systems,Ministry of Education,Defense Key Disciplines Laboratory of Novel Micro-Nano Devices and System Technology,College of Optoelectronic Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]重庆大学光电技术及系统教育部重点实验室,新型微纳器件与系统技术国防重点学科实验室,重庆400044

出　　处：《压电与声光》2022年第5期691-695,共5页Piezoelectrics & Acoustooptics

基　　金：重庆市博士“直通车”科研项目(CSTB2022BSXM-JSX0004);中国科学院“西部之光”人才培养引进计划;中央高校基本科研业务费(2021CDJQY-041)。

摘　　要：该文研究了一种薄膜体声波谐振器(FBAR)采用并联电感和外匹配电路的拓扑结构实现宽带滤波的方法。使用Comsol软件对FBAR进行三维结构仿真,并提取最优电极形状(变迹五边形)对应曲线到ADS中联合外匹配电路进行频带拓展,外匹配电路中的电感L_(s)取值直接影响滤波器带宽。经调节,最终在谐振器串联谐振频率f_(s)=1.97 GHz,并联谐振频率f_(p)=2.03 GHz的情况下实现了21.15%的相对带宽,此时对应的3 dB带宽为419 MHz,1 GHz处的带外抑制为11.616 dB。In this paper,a thin film bulk acoustic wave resonator(FBAR)with a topology of parallel inductors and an external matching circuit was used to realize broadband filtering.A 3D structure simulation of FBAR was performed using Comsol software to extract the curve corresponding to the optimal electrode shape(variable trace pentagon)into the ADS in conjunction with the external matching circuit for band expansion.It was found that the values of inductor L_(s) in the external matching circuit directly affect the filter bandwidth.After adjustment,the relative bandwidth of 21.15%was achieved at the series resonant frequency of f_(s)=1.97 GHz and parallel resonant frequency of f_(p)=2.03 GHz,which corresponds to a 3 dB bandwidth of 419 MHz and an out-of-band rejection of 11.616 dB at 1 GHz.

关 键 词：薄膜体声波谐振器(FBAR) 有限元仿真 MBVD模型 宽带 拓扑结构 

分 类 号：TN65[电子电信—电路与系统] TN713TN75