In this study, we have scrutinized the frequency gap generation by changing the geometrical parameters of a one-dimensional phononic crystal. For this purpose, we have calculated the transmission coefficient of an incident acoustic wave by using the transfer matrix method. We have retained and fixed the total length of the system and changed the system internal geometry not to increase the system length too much. Another reason was to adjust the phononic band gaps and get the desired transmission properties by finding the optimum internal geometry without increasing or decreasing the total length of phononic crystals. In addition, we also propose few structures with the opportunity of applications in acoustical devices such as sonic reflectors. Our results can also be of high interest to design acoustic filters in the case that transmission of certain frequencies is necessary.

中文翻译：

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Al/Pb 多层恒定总长度声子晶体中的声波频率滤波

在这项研究中，我们通过改变一维声子晶体的几何参数来仔细检查频隙的产生。为此，我们使用传递矩阵法计算了入射声波的透射系数。我们保留并固定了系统的总长度，并更改了系统内部几何形状，以免过多地增加系统长度。另一个原因是通过在不增加或减少声子晶体总长度的情况下找到最佳内部几何形状来调整声子带隙并获得所需的传输特性。此外，我们还提出了一些具有在声学设备（例如声反射器）中应用的机会的结构。