基于二维正方晶格声子晶体滤波器的直接耦合结构, 研究了点缺陷的位置和大小对透射率的影响, 从而设计出性能最佳的声子晶体滤波器。利用时域有限差分方法, 使用COMSOL软件进行仿真, 讨论了点缺陷对声子晶体滤波器性能的影响。仿真结果表明: 当直接耦合声子晶体滤波器的点缺陷位于线缺陷中间位置、点缺陷处介质柱的填充率为0.0228时, 滤波器的透射率高达92%, 符合设计要求。

Based on the direct coupling structure of two-dimensional square lattice phononic crystal filter, the influence of location and size of point defects on the transmittance of phonon crystal were studied, thus the optimal phononic crystal filter was designed. Using the FDTD method, the effects of point defects on the transmittance of filter were discussed by the simulations performed with COMSOL software. It is concluded that when the location of point defects of direct-coupling phononic crystal filter is in the middle of line defect and the filling factor of media column at point defects is 0.0228, the transmittance can achieve 92%, meeting the design demand.