Theory and simulations predict the metamaterial-enhanced resistive wall amplifier (MERWA) may offer improvements to megawatt-level high-power microwave (HPM) amplifiers in terms of combined bandwidth and gain rates. A low-power proof-of-concept test prototype has been designed using a metamaterial (MTM) consisting of a linear array of periodically spaced thin lossy meandered wires. Direct simulations of these arrays of thin meandering wires using typical 3-D particle-in-cell (PIC) solvers are inaccurate, creating significant challenges for obtaining trustworthy hot test simulations of the prototype device. This work enables predictive PIC simulations of the experimental MERWA prototype by replacing the thin lossy wire structure with an equivalent effective-medium model. We find that a finite-width rod having an anisotropic Drude–Lorentz permittivity is a suitable model to replace the lossy wire MTM structure. We detail our modeling process and assumptions, fitting procedures, and model fitting results. The model is validated by comparing PIC simulations to experimental results.

中文翻译：

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用于细胞内粒子模拟的曲折线超材料增强电阻壁放大器电路的有效介质建模

理论和模拟预测超材料增强电阻壁放大器 (MERWA) 可能会在组合带宽和增益率方面为兆瓦级高功率微波 (HPM) 放大器提供改进。低功耗概念验证测试原型已使用超材料 (MTM) 设计，该超材料 (MTM) 由周期性间隔的细有损曲折线的线性阵列组成。使用典型的 3-D 单元内粒子 (PIC) 求解器对这些细曲折线阵列的直接模拟是不准确的，这给获得原型设备的可靠热测试模拟带来了重大挑战。这项工作通过用等效的有效介质模型替换细有损线结构，使实验性 MERWA 原型的预测 PIC 模拟成为可能。我们发现具有各向异性 Drude-Lorentz 介电常数的有限宽度杆是替代有损线 MTM 结构的合适模型。我们详细介绍了我们的建模过程和假设、拟合程序和模型拟合结果。通过将 PIC 模拟与实验结果进行比较来验证该模型。