超宽带低损耗SAW滤波器的优化设计  

The Optimal Design of Ultra-Wideband Low Loss SAW Filter

作　　者：黄歆 闫坤坤 黄玮 魏勇平 HUANG Xin;YAN Kunkun;HUANG Wei;WEI Yongping(Beijing Zhongke Feihong Science & Technology CO.,LTD,Beijing 100095, China)

机构地区：[1]北京中科飞鸿科技有限公司,北京100095

出　　处：《压电与声光》2020年第2期155-158,共4页Piezoelectrics & Acoustooptics

摘　　要：该文介绍了基于大机电耦合系数乐甫波模式的超宽带低损耗声表滤波器的开发,基底为15°YX-LiNbO3晶体和铜电极。设计采用修正的耦合模模型进行精确仿真以及模拟退火算法进行谐振器参数的优化。通过假指电极宽度/长度加权来抑制横向模式谐振造成的寄生响应,通过在滤波器表面涂覆黏性膜来有效抑制瑞利波模式造成的寄生凹坑,最终制作出一款中心频率约620 MHz,插损0.94 dB,-1 dB相对带宽14.9%,-3 dB相对带宽18.3%,带外抑制大于40 dB性能较优良的器件。This paper describes the development of ultra-wideband and very low-loss SAW filter based on the large electromechanical coupling coefficient Love wave mode,a Cu electrode/15°YX-LiNbO3 structure was employed as a substrate.The design adopts the modified coupled mode model for accurate simulation and simulated annealing algorithm for the optimization of resonator parameters.The width/length weighted dummy electrodes were used to suppress spurious responses caused by the transverse-mode resonances,and a viscous film was coated on the filter surface which is effective in suppress a spurious dip caused by Rayleigh mode.A filter with the center frequency of 620 MHz,-1 dB fractional bandwidth of 14.9%,-3 dB bandwidth of 18.3%,insertion loss of 0.94 dB,and out-of-band rejection of higher than 40 dB was fabricated.

关 键 词：声表面波滤波器 超宽带 铜电极/15°YX-LiNbO3 

分 类 号：TN65[电子电信—电路与系统] TN384