A low-loss and wide-band DMS filter using pitch-modulated IDT and reflector structures
A low-loss and wide-band DMS filter using pitch-modulated IDT and reflector structures
复制标题
使用音调调制 IDT 和反射器结构的低损耗宽带 DMS 滤波器
DOI：
10.1109/ultsym.2004.1417725
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
K. Hashimoto
中科院分区：
文献类型：
--
作者：
O. Kawachi;S. Mitobe;M. Tajima;T. Yamaji;S. Inoue;K. Hashimoto
本文提出了使用间距调制叉指换能器和反射器的低损耗和宽带纵向耦合双模SAW（DMS）滤波器的实现。该技术通过在DMS滤波器设计中引入足够数量的DoF来大幅改善器件性能。即，通带变得宽而平坦，并且可以通过体声波（BAW）散射的抑制来减小插入损耗。首先，它示出了如何BAW的散射损耗可以通过使用的间距调制的结构来减少。设计了具有这种结构的DMS滤波器，使得频率响应变得类似于具有常规未调制结构的滤波器的频率响应，并且从理论和实验两方面比较了器件性能。然后，它演示了如何通过使用这种技术的总设备的性能得到改善时，该设备的最佳设计为给定的规格。除了降低体波散射损耗外，各种独特的功能还大大提高了整个器件的性能。
This paper proposes the use of pitch-modulated IDTs and reflectors for the realization of low-loss and wideband longitudinally coupled double-mode SAW (DMS) filters. This technique offers drastic improvement of the device performance through the introduction of a sufficient number of DoF in the DMS filter design. Namely, the pass-band becomes wide and flat, and insertion loss can be reduced through the suppression of the bulk acoustic wave (BAW) scattering. First, it is shown how the BAW scattering loss can be reduced by the use of the pitch-modulated structure. The DMS filter with this structure is designed so that the frequency response becomes similar to that of the filter with the conventional un-modulated structure, and device performances are compared both theoretically and experimentally. Then it is demonstrated how the total device performances are improved by the use of this technology when the device is designed optimally for given specifications. Adding to the reduced bulk wave scattering loss, various distinctive features offer drastic improvement of total device performances.