Realization of high-performance bandpass filter by impedance-mirroring
Realization of high-performance bandpass filter by impedance-mirroring
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DOI：
10.1016/j.jsv.2015.06.006
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发表时间：
2015-10-27
影响因子：
4.7
通讯作者：
Kim, Yoon Young
中科院分区：
文献类型：
--
作者：
Lee, Il Kyu;Seung, Hong Min;Kim, Yoon Young
理想的带通滤波器必须在目标通带上同时具有陡峭的滚降和高的透射率，但是仍然难以使这样的滤波器具有合理的尺寸。为了实现这样的性能，我们提出了一种新的有限声子晶体滤波器制成的阻抗镜元件，每个元件由两个层具有不同的阻抗。对于宽带通滤波，两层中的一层被选择为在通带的中心频率处的八分之一波长长，而另一层被选择为具有匹配阻抗的四分之一波长长。对于窄带通滤波，宽带通滤波器被稍微修改，使得阻抗镜像的概念被全局地应用于有限周期结构滤波器，而不是在每个单元内。为了检查所提出的过滤器的性能，实验中使用杆中的扭转弹性波进行。(C)2015爱思唯尔有限公司版权所有。
Ideal bandpass filters must have sharp roll-off and high transmission over a target pass band simultancoulsy, but it is still difficult to make such filters of a reasnoable size. To achieve such performance, we propose a novel finite phononic crystal filter made of impedance-mirrored elements each of which constists of two layers having different impedances. For broad bandpass filtering, one of the two layers is selected to be one eighth wavelength long at the center frequency of the passband and the other layer, one quarter wavelength long with a matched impedance. For narrow bandpass filtering, the broad bandpass filter is slightly modified in such a way that the concept of the impedance mirroring is applied globally over the finite periodic structure filter, not within each unit cell. To check the performance of the proposed filters, experiments using torsional elastic waves in a rod were conducted. (C) 2015 Elsevier Ltd. All rights reserved.