提出了一种应用于能量收集的新型三频微带整流天线, 该接收天线为一种新型高增益三频贴片天线. 首先, 在贴片两侧刻蚀U字形槽, 延长表面电流路径, 使天线谐振频点向低频偏移, 从而使天线小型化; 其次, 在矩形贴片刻蚀H型槽和倒U型槽, 改变天线上的电流分布来产生2个新的谐振点; 最后, 合理调节H型槽和倒U型槽的长度, 灵活改变天线的谐振频率. 整流电路由阻抗匹配网络、整流二极管、直通滤波器和负载组成. $\Pi $型和T型二级阻抗匹配网络, 用于接收天线和整流二极管输入阻抗的匹配; 四分之一波长微带线和滤波电容组成的直通滤波器, 用于抑制二极管非线性产生的高次谐波, 以避免能量的损失. 将接收天线和整流电路集成为整流天线, 实验结果表明, 在接收功率为3 dBm左右时, 整流天线在3个频点2.06、3.43和5.25 GHz处的最大整流效率为54.1%、 43.9%和39.9%, 可用于物联网中的低功耗电子设备供电.

A novel triple-band microstrip patch rectenna was proposed for energy collection, and the receiving antenna was a new triple-band patch antenna with high gain. First, a U-shaped slot was etched on both sides of the patch to extend the path of the surface current; this ensured that the resonant frequency shifted to a low frequency and that the patch antenna was miniaturized. Second, by etching an H-slot and a U-slot on the rectangular patch, the current distribution was altered, and two new resonance frequencies were generated. The resonant frequencies of the antenna could be modified by adjusting the lengths of the H-slot and the inverted U-slot. The rectifier consisted of an impedance matching network, a rectifying diode, a pass-through filter, and a load. The two-stage matching network consisted of $\Pi$-type and T-type networks for matching the input impedance of the receiving antenna and the rectifying diode. A pass-through filter comprising a quarter-wavelength microstrip line and a filter capacitor was used to suppress high-order harmonics generated by diode nonlinearity in order to avoid energy loss. The receiving antenna and the rectifier were integrated as the rectenna. The experimental results show that, when the receiving power is approximately 3 dBm, the maximum efficiency of the rectenna is 54.1%, 43.9%, and 39.9% at 2.06, 3.43, and 5.25 GHz, respectively. Therefore, the rectenna can be used for the power supply of low-power electronic devices in the Internet of Things.