第二类椭圆型声表面波滤波器的设计  

Design of Narrow Bandwidth Elliptic-type Ⅱ SAW Filters

作　　者：王华磊 钟慧[2] 石玉[2] 李利平 周林生 

机构地区：[1]成都燎原星光电子有限责任公司,四川成都610100 [2]电子科技大学电子薄膜与集成器件国家重点实验室,四川成都610054

出　　处：《压电与声光》2013年第6期786-787,791,共3页Piezoelectrics & Acoustooptics

摘　　要：梯形滤波器的带宽由基片的机电耦合系数决定,当基片选择后,相对带宽基本固定。该文提出了一种椭圆型声表面波滤波器,在同一基片上特别是压电性强的基片上,可灵活控制滤波器的相对带宽。由于电容比的存在,声表面波谐振器取代椭圆LC滤波器中的谐振单元后,额外的零点和极点出现在通带两侧。引入模拟退火法对各个谐振器的静态电容进行优化,得到了窄带低损耗高矩形度的滤波器。实验证明了该方法的有效性。The passband width obtained in the SAW ladder filter is inherently limited by the electromechanical coupling factor of piezoelectric substrate.A kind of elliptic SAW filter is proposed in this paper.The relative bandwidth of the attainable filter can be controlled flexibly on the same substrate,especially on the strong piezoelectric substrate.Due to the capacitance ratio γ,the additional zero-point and pole-point are appeared at the two sides of the passband after the resonators in the elliptic LC filter are replaced by SAW resonators.The static capacitor of each resonator are optimized by introducing the simulation annealing,thus the narrow-band,low loss filter with high shape factor has been realized.The effect of the design technique is verified by the experiment.

关 键 词：椭圆滤波器 声表面波谐振器 15°YX-LiNbO3 

分 类 号：TN384[电子电信—物理电子学] TN65