A flexible broadband antenna with high radiation efficiency for the Internet of Things (IoT) applications is presented. The design is based on a U-shaped and a triangular-shaped radiator with two tuning stubs. A 50 Ω coplanar waveguide (CPW) transmission line is employed to feed the antenna. The proposed antenna is fabricated on a flexible substrate from a composite synthesized by mixing natural rubber with SiO2 as a filler. The radiating elements, along with the CPW, are built using a highly conductive woven fabric. Results show that the antenna has a simulated and measured impedance bandwidth of 0.856–2.513 GHz and covers the most commonly used wireless communication standards and technologies for IoT applications. The radiation efficiency of the antenna reaches over 75% throughout the operating frequency band with satisfactory radiation patterns and gain. The flexible antenna was also tested under bending conditions. The presented results demonstrate that bending has a minor effect on the antenna performance within the target frequency range. The measured results show a good agreement with simulations.

中文翻译：

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用于物联网应用的灵活宽带天线

提出了一种用于物联网 (IoT) 应用的具有高辐射效率的柔性宽带天线。该设计基于带有两个调谐短柱的 U 形和三角形散热器。采用 50 Ω 共面波导 (CPW) 传输线为天线供电。所提出的天线是在柔性基板上制造的，由天然橡胶与 SiO2 混合合成的复合材料制成2作为填充物。辐射元件与 CPW 一起使用高导电织物制成。结果表明，该天线的模拟和测量阻抗带宽为 0.856–2.513 GHz，涵盖了物联网应用中最常用的无线通信标准和技术。该天线的辐射效率在整个工作频段内均达到75%以上，具有令人满意的辐射方向图和增益。柔性天线也在弯曲条件下进行了测试。所呈现的结果表明，弯曲对目标频率范围内的天线性能影响较小。实测结果与模拟结果吻合良好。