In this paper, an unconditionally stable time-domain method is proposed to investigate the external electromagnetic (EM) field illumination on the nonlinearly loaded transmission lines. In the proposed algorithm, the field to line coupling equations and linear/nonlinear boundary conditions are incorporated and expressed in a matrix form. The derived differential matrix equations are then discretized and solved using the proposed finite difference time domain (FDTD) method approach. The discretized nonlinear matrix equations are also solved by applying a globally convergent iterative method to ensure the stability of the method. Moreover, the experimental investigations are conducted using a transverse EM (TEM) cell for a single microstrip line and a power detector circuit as a nonlinearly loaded transmission line to confirm the accuracy and stability of the proposed method. With the merit of satisfactory accuracy and unconditional stability for the entire range of time steps, the presented approach would be applicable for analyzing the microwave linear/nonlinear circuits subjected to the external incident EM wave.

中文翻译：

---

非线性终端传输线电磁波照射分析

在本文中，提出了一种无条件稳定时域方法来研究非线性负载传输线上的外部电磁 (EM) 场照明。在所提出的算法中，场到线耦合方程和线性/非线性边界条件被合并并以矩阵形式表示。然后使用所提出的有限差分时域 (FDTD) 方法方法对导出的微分矩阵方程进行离散化和求解。离散化的非线性矩阵方程也采用全局收敛迭代法求解，保证了方法的稳定性。而且，实验研究是使用用于单条微带线的横向 EM (TEM) 单元和作为非线性负载传输线的功率检测器电路进行的，以确认所提出方法的准确性和稳定性。由于在整个时间步长范围内具有令人满意的精度和无条件稳定性的优点，所提出的方法将适用于分析受到外部入射电磁波影响的微波线性/非线性电路。