This paper presents an efficient hybrid method consisting of Lorentz reciprocity theorem, finite-difference-time-domain (FDTD) method, thin wire model, transmission line (TL) equations and transfer impedance model, which can be utilized to analyze the system-level transient responses of the microstrip antenna system with antenna, metallic enclosures, braided shielded cable, and lumped element, when illuminated by an external electromagnetic pulse (EMP). In order to avoid over-fine mesh generation and repeated modeling of the antenna in multiple simulations, Lorentz reciprocity theorem is employed to extract an equivalent source model of antenna coupling, thereby improving the computational efficiency. Then, the transfer impedance model and thin wire model are incorporated into the FDTD-TL method efficiently to deal with the back-door coupling through the shielding layer of feeding coaxial cable. Finally, the hybrid FDTD method combined with the extracted equivalent source of antenna coupling is utilized to solve the coupling responses of the whole antenna system. The results of numerical simulation are verified by comparing with the simulation results of CST CS. Then, considering the influence of different incident conditions of external EMP, the characteristics of the coupling response of the system are analyzed. The obtained coupling response information demonstrate that the proposed method is available for further designing electromagnetic protection of the inner circuits of the microstrip antenna system against the impact of external EMP.

中文翻译：

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一种分析微带天线系统耦合响应的高效混合方法

本文提出了一种高效的混合方法，包括洛伦兹互易定理、时域有限差分 (FDTD) 方法、细线模型、传输线 (TL) 方程和传输阻抗模型，可用于分析系统级当受到外部电磁脉冲 (EMP) 照射时，具有天线、金属外壳、编织屏蔽电缆和集总元件的微带天线系统的瞬态响应。为了避免天线在多次仿真中网格生成过细和重复建模，采用洛伦兹互易定理提取天线耦合等效源模型，从而提高计算效率。然后，传输阻抗模型和细线模型被结合到FDTD-TL方法中，以有效地处理通过馈电同轴电缆屏蔽层的后门耦合。最后利用混合FDTD方法结合提取的天线耦合等效源求解整个天线系统的耦合响应。通过与CST CS的模拟结果进行对比，验证了数值模拟结果。然后，考虑外部电磁脉冲不同入射条件的影响，分析了系统的耦合响应特性。获得的耦合响应信息表明，所提出的方法可用于进一步设计微带天线系统内部电路的电磁保护以抵抗外部 EMP 的影响。