Converting Radio Frequency waves to Electrical Energy using Metamaterials

We designed a high-efficiency radio frequency (RF) energy harvesting device using a metamaterials perfect absorber (MPA). With the embedded Schottky diodes, the device converts RF waves to DC electricity. The MPA design greatly improves the amount of RF energy captured by the device. The Fabry-Perot (FP) cavity resonance of the MPA further increases the voltage across the Schottky diodes significantly, allowing the diodes to turn on at a very low intensity of the incident waves. Therefore our device can harvest low-intensity RF waves, such as ambient RF waves of cell phone networks or WiFi networks. Numerical simulations were performed to improve the device performance by investigating different design parameters. The optimized design consists of a 4x4 array of split-ring resonators (SRR) and a metal plate separated by a small cavity of 4 cm. The resulting design is 21x19 cm in size with each SRR having 3.75 cm side lengths and an 8 mm gap.