This paper reports on a dual-band, polarization-insensitive frequency-selective surface (FSS) directly realized on window glass for Wi-Fi and WLAN shielding applications. The design incorporates an annular ring and modified flower-shaped geometry to suppress 2.45 and 5.5 GHz bands, respectively, while acting ineffective to the rest of the frequency spectrum. The proposed design is completely insensitive to incoming wave polarization owing to its symmetry. The FSS also offers excellent incident wave angular stability up to 45°. Additionally, a wide rejection bandwidth (−10 dB) of more than 630 and 1430 MHz for lower and higher bands, respectively, is obtained suffice to cover the WLAN spectrum. Unlike conventional screen-printed FSS for glass applications, the conducting patterns of the proposed FSS are realized with copper foil directly laminated and etched on the glass substrate while maintaining 86% transparency for sufficient light passage. The detailed analysis of all parameters has been carried out, and their effect on the performance of FSS is reported. An equivalent lumped circuit model is also generated for the proposed design to better understand the physical phenomena of electromagnetic (EM) wave suppression. A finite prototype containing 13 × 10 elements is fabricated and tested. The measured results are in good agreement with the simulated ones. The FSS offers measured suppression of 43 and 40 dB at 2.45 and 5.5 GHz bands, respectively. The design has excellent potential for EM field suppression, WLAN isolation, and security applications in indoor environments.

中文翻译：

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用于通过玻璃窗进行射频屏蔽的偏振不敏感双频带频率选择表面

本文报道了直接在窗户玻璃上实现的双频段、偏振不敏感频率选择表面 (FSS)，用于 Wi-Fi 和 WLAN 屏蔽应用。该设计包含一个环形环和改进的花形几何形状，分别抑制 2.45 和 5.5 GHz 频段，同时对其余频谱无效。由于其对称性，所提出的设计对入射波极化完全不敏感。FSS 还提供高达 45° 的出色入射波角稳定性。此外，获得的低频段和高频段分别超过 630 和 1430 MHz 的宽抑制带宽 (-10 dB) 足以覆盖 WLAN 频谱。与用于玻璃应用的传统丝网印刷 FSS 不同，所提出的 FSS 的导电图案是通过直接层压和蚀刻在玻璃基板上的铜箔实现的，同时保持 86% 的透明度以提供足够的光通过。对所有参数进行了详细分析，并报告了它们对 FSS 性能的影响。还为建议的设计生成了等效的集总电路模型，以更好地了解电磁 (EM) 波抑制的物理现象。制造并测试了一个包含 13 × 10 个元素的有限原型。实测结果与模拟结果吻合较好。FSS 在 2.45 和 5.5 GHz 频段分别提供 43 和 40 dB 的测量抑制。该设计在室内环境中的 EM 场抑制、WLAN 隔离和安全应用方面具有出色的潜力。