This letter presents a novel multiband rectenna for the ambient wireless energy harvesting of an autonomous internet of thing (IoT) sensor. A bow-tie antenna with slits is proposed to obtain four frequency bands at 840 MHz, 1.86, 2.1, and 2.45 GHz, respectively. Furthermore, a multiband rectifying circuit combined of four single ring-loop rectifiers is designed with high conversion efficiency. Finally, a power management circuit with storing and converting the harvested voltage is proposed for smoothing dc output voltage. The energy harvester can be used in practical wireless sensor applications.

中文翻译：

---

自主物联网设备的多频段环境射频能量收集

这封信提出了一种新颖的多频段整流天线，用于自主物联网 (IoT) 传感器的环境无线能量收集。提出了一种带狭缝的领结天线，分别在 840 MHz、1.86、2.1 和 2.45 GHz 获得四个频段。此外，还设计了一个由四个单环回路整流器组合而成的多频段整流电路，转换效率高。最后，提出了一种具有存储和转换采集电压的电源管理电路，用于平滑直流输出电压。能量收集器可用于实际的无线传感器应用。