低插损窄带TCSAW滤波器的设计与研制  

Design and Development of Narrow-Band TCSAW Filter with Low Insertion Loss

作　　者：黄亮[1] 周亚男 王志超 何朝峰 朱卫俊[1] HUANG Liang;ZHOU Yanan;WANG Zhichao;HE Chaofeng;ZHU Weijun(CETC Deqing Huaying Electronics Co.,Ltd.,Nanjing 210016,China)

机构地区：[1]中电科技德清华莹电子有限公司,江苏南京210016

出　　处：《压电与声光》2024年第3期300-305,共6页Piezoelectrics & Acoustooptics

摘　　要：为了减小窄带滤波器的插入损耗,在梯形拓扑的基础上引入并联电容,提出了一种并联电容型梯形拓扑。利用并联电容大幅度改变反谐振点频率的特点,以牺牲较小插入损耗的代价来缩小带宽。通过谐振器设计与进化算法寻优,成功研制出一款基于SiO_(2)/Cu/127°YX-LiNbO3结构的低插损窄带温补型声表面波(TCSAW)滤波器。实验结果表明,滤波器的中心频率为1514 MHz,相对带宽为0.46%,带内插入损耗仅1.45 dB,过渡带20 MHz带外抑制滚降到24 dB,远带带外抑制大于30 dB,WiFi频段抑制高达48 dB,频率温度系数TCF为-20×10^(-6)/℃,器件尺寸为1.1 mm×0.9 mm。A shunt-capacitance-type ladder-type topology was proposed by adding a shunt capacitance in a laddertype topology to further reduce the insertion loss of a narrow-band filter.The shunt capacitance was used to modify the anti-resonant frequency of the resonator for reducing the bandwidth of the filter with sacrificing low insertion loss.A narrow-band temperature compensated SAW(TCSAW)filter with low insertion loss based on a SiO_(2)/Cu/127°YX-LiNbO3 structure was developed successfully via resonator design and evolutionary algorithm optimization.The experimental results indicate that the center frequency of the filter,relative bandwidth,and passband insertion loss are 1514 MHz,0.46%,and only 1.45 dB,respectively.Further,the attenuation at the frequency 20 MHz outside the passband decreases to 24 dB,remote out-of-band attenuation is greater than 30 dB,attenuation at the WiFi band is up to 48 dB,TCF is-20×10^(-6)/℃,and the size of the device is 1.1 mm×0.9 mm.

关 键 词：温补型声表面波滤波器 梯形拓扑 并联电容 窄带 低插损 

分 类 号：TN65[电子电信—电路与系统] TN713