2.5维圆波导开放边界截断的修正完全匹配层方法

 在时域有限差分算法中，完全匹配层是一种高效的吸收边界条件。通过在标准完全匹配层(PML)方程中添加具有物理意义的电导率和导磁率附加项，提出了修正完全匹配层(MPML)方法，给出了圆柱坐标下3维MPML方程，并应用于2.5维圆波导开放边界的截断计算。计算结果表明，在不同频率和模式的激励下，加入平滑电导率和导磁率附加项后，与标准PML方法相比，MPML方法的相对误差降低8~10 dB。

Modified perfectly matched layer for truncation of open boundary of cylindrical waveguide in 2.5 dimensional simulation

In the finite-difference time-domain(FDTD) method,the perfectly matched layer(PML) is a kind of high efficient absorbing boundary condition.By adding the terms of physical electric conductivity and magnetic conductivity in the conventional PML equations,a modified PML(MPML) method is presented.Three dimensional MPML equations in the cylindrical coordinate system are given and applied to truncate the open boundary of cylindrical waveguide in 2.5-dimensional simulation.Under the excitations of various modes with different frequencies,the relative errors obtained using the MPML method are 8~10 dB lower than those obtained by the conventional PML method.