中文说明：利用频域有限差分法，YEE网格求解二维矩形双脊波导的本征值，再转化为截止频率。通过和HFSS的计算结果进行对比，可以得出结果精确的结论。
English Description：
The eigenvalues of two-dimensional rectangular double ridged waveguide are solved by the finite difference method in frequency domain and Yee grid, and then converted to the cut-off frequency. By comparing with the results of HFSS, we can get an accurate conclusion.