利用辅助场时域有限差分(FDTD)方法分析色散周期结构的斜入射问题.主要基于Floquet定理,在FDTD迭代式中引入辅助场量,结合变换的周期及吸收边界条件,解决了周期结构斜入射问题的电磁特性仿真.进一步将辅助场FDTD方法引入至色散周期结构的模拟,结合Z变换方法,给出了基于Drude色散模型的具体迭代公式.数值计算结果表明所构建方法的有效性及普适应. Based on the Floquet theorem, an auxiliary field is introduced into the FDTD iterative method, which combines the transformation cycle and the absorption boundary conditions to solve the problem of oblique incidence of periodic structures And the simulation of the electromagnetic properties of the problem.Furtherly, the auxiliary field FDTD method is introduced into the simulation of the dispersion periodic structure and the Z iterative method is combined to give the concrete iterative formula based on the Drude dispersion model.The numerical results show that the proposed method is effective and universal .