Resonator Rectenna Design Based on Metamaterials for Low-RF Energy Harvesting

In this paper, the design of a resonator rectenna, based on metamaterials and capable of harvesting radio-frequency energy at 2.45 GHz to power any low-power devices, is presented. The proposed design uses a simple and inexpensive circuit consisting of a microstrip patch antenna with a mushroom-like electromagnetic band gap (EBG), partially reflective surface (PRS) structure, rectifier circuit, voltage multiplier circuit, and 2.45 GHz Wi-Fi module. The mushroom-like EBG sheet was fabricated on an FR4 substrate surrounding the conventional patch antenna to suppress surface waves so as to enhance the antenna performance. Furthermore, the antenna performance was improved more by utilizing the slotted I-shaped structure as a superstrate called a PRS surface. The enhancement occurred via the reflection of the transmitted power. The proposed rectenna achieved a maximum directive gain of 11.62 dBi covering the industrial, scientific, and medical radio band of 2.40–2.48 GHz. A Wi-Fi 4231 access point transmitted signals in the 2.45 GHz band. The rectenna, located 45 anticlockwise relative to the access point, could achieve a maximum power of 0.53 μW. In this study, the rectenna was fully characterized and charged to low-power devices.