Unlike conventional energy harvesters that are tuned to individual frequencies and are directional, the proposed wideband (23% fractional bandwidth), omnidirectional system harvests from all FM towers in vicinity. Hence, it does not require each sensor node to be carefully aligned to any one source and makes itself suited for mass-deployment applications such as precision agriculture and structural health monitoring. It harvests as much as 923 $\mu \text{W}$ on a rooftop at 1.54 km from an FM tower while retaining omnidirectionality partly thanks to the proposed antenna, which has a wider bandwidth and a higher measured gain (2.0 dBi) than the commercial reference wideband antenna. It achieves competitive efficiency (56%) and sensitivity (−17 dBm) while retaining wideband operation rather than being specifically optimized to individual frequencies. The system (fabricated on low-cost FR4) harvested outside ambient FM energy indoors at the same 1.54-km location to power a wireless sensor node without needing to shut down periodically.

中文翻译：

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用于永久物联网的宽带、准各向同性、公里范围的 FM 能量收集器

与调谐到单个频率和定向的传统能量收集器不同，提议的宽带（23% 部分带宽）全向系统从附近的所有 FM 发射塔收集能量。因此，它不需要每个传感器节点与任何一个源仔细对齐，并且使其适合大规模部署应用，例如精准农业和结构健康监测。它在距离 FM 塔 1.54 公里的屋顶上收获了多达 923 $\mu \text{W}$，同时保留了全向性，部分原因是提议的天线具有更宽的带宽和更高的测量增益（2.0 dBi）。商用参考宽带天线。它实现了具有竞争力的效率 (56%) 和灵敏度 (−17 dBm)，同时保持了宽带操作，而不是专门针对单个频率进行了优化。