AlN薄膜体声波梯形滤波器的制备与性能分析

用Mason一维等效电路模型模拟了不同级数的梯形体声波滤波器的传输特性.讨论了谐振器级联数对滤波器插入损耗和带外抑制的影响.以AlN薄膜为压电材料,采用微机电系统(MEMS)工艺流程制备了3级梯形结构的滤波器,用扫描电镜照片(SEM)和网络分析仪表征了器件的结构和传输响应特性,测试结果表明,所制备的滤波器结构完整,图形整齐,并得到滤波器的带宽为180 MHz,带外衰减为-10.12 dB,插入损耗为-5.15 dB.

Study on Bulk Acoustic Wave Ladder Filter Using AlN Thin Film

The transmission performances of film bulk acoustic wave filter with different stage number of ladders were simulated adopting one dimensional Mason model.The effect of the cascaded resonators on the insertion loss and out-of-band rejection of the filter was discussed.Three-ladder filter was fabricated by MEMS techniques using AlN film as the piezoelectric material.The structure and transmission performance were analyzed by SEM and network analyzer.The results indicated that the image of fabricated filter was intact and the shape of resonated area is regular.The band width is 180MHz; the out-of-band rejection and the insertion loss of is -10.12 dB and -5.15 dB respectively.