中文说明：二维声子晶体FDTD方法计算禁带宽度的例子,一个计算声子晶体结构的一维传递矩阵法,窗函数法设计一个数字带通FIR滤波器，调试通过可以使用，实现串口的数据采集，有CDF三角函数曲线/三维曲线图。
English Description：
Two-dimensional Photonic Crystal FDTD method for calculating band case, a calculation of the transfer matrix method for one-dimensional Photonic crystal structure, window function to design a digital bandpass FIR filters, debugging can use to realize serial data acquisition, CDF trigonometric curve/three-dimensional graph.