A local permittivity model is proposed to accurately characterize spatial dispersion (SD) in nonlocal wire medium (WM) structures with arbitrary terminations. A closed-form expression for the local thickness-dependent permittivity is derived for a general case of a bounded WM with lumped impedance insertions and terminated with impedance surfaces, which takes into account the effects of SD and loads/terminations in the averaged sense per length of the wire medium. The proposed approach results in a local model formalism and accurately predicts the response of WM structures for near-field and far-field excitation. It is also shown that a traditional transmission network and circuit model can be effectively used to quantify the interaction of propagating and evanescent waves with WM structures. In addition, the derived analytical expression for the local thickness-dependent permittivity has been used in the full-wave numerical solver (CST Microwave Studio) demonstrating a drastic reduction in the computation time and memory in the solution of near-field and far-field problems involving wire media.

中文翻译：

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非局部导线介质的有效局部介电常数模型

提出了一种局部介电常数模型，以准确表征具有任意终端的非局部导线介质 (WM) 结构中的空间色散 (SD)。对于具有集总阻抗插入并以阻抗表面终止的有界 WM 的一般情况，推导出局部厚度相关介电常数的封闭形式表达式，其中考虑了每长度平均意义上的 SD 和负载/终端的影响线介质。所提出的方法产生局部模型形式，并准确预测 WM 结构对近场和远场激发的响应。还表明，传统的传输网络和电路模型可以有效地用于量化传播和渐逝波与 WM 结构的相互作用。此外，