采用FDTD算法仿真矩型脊波导TM模色散曲线-The finite difference time domain Maxwell equations in the field of time and space differencing. Leapfrog space in the field of electric and magnetic fields alternate calculation, updated by the time field to mimic the changes in the electromagnetic field, to achieve the purpose of numerical calculation. The analysis of the problem to consider the geometric parameters of the object of study, the material parameters, calculation accuracy, computational complexity, computational stability and many other issues. The advantage is the ability to direct simulation of field distribution, the accuracy is relatively high, and is currently one of the more numerical simulation method.This course designe using the finite difference method combined with double-ridged rectangular waveguide boundary conditions to solve the fundamental mode of the waveguide and the first higher order mode dispersion curve.