This paper presents a full electromagnetic (EM) characterization of metallic lenses. The method is based on the utilization of free-space transmission and reflection coefficients to accurately obtain lenses’ tensorial EM parameters. The applied method reveals a clear anisotropic behavior with a full tensorial directional permittivity and permeability and noticeably dispersive permeability and wave impedance. This method yields accurate values for the effective refractive index, wave impedance, permittivity, and permeability, unlike those obtained by simple methods such as the eigenmode method. These correct cell parameters affect their lens performance, as manifested in a clear level of anisotropy, impedance matching, and losses. The effect of anisotropy caused by oblique incidence on the performance and operation of lens designs is illustrated in a lens design case.

中文翻译：

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金属透镜结构的各向异性表征

本文介绍了金属透镜的全电磁 (EM) 表征。该方法基于利用自由空间透射系数和反射系数来准确获得透镜的张量电磁参数。所应用的方法显示出清晰的各向异性行为，具有完整的张量方向介电常数和磁导率以及显着的色散磁导率和波阻抗。与通过简单方法（如本征模式方法）获得的值不同，该方法可得出有效折射率、波阻抗、介电常数和磁导率的准确值。这些正确的电池参数会影响它们的透镜性能，这体现在各向异性、阻抗匹配和损耗的明显水平上。