Triple-band polarization-insensitive and wide-angle metamaterial array for electromagnetic energy harvesting

Abstract

This work demonstrated a metamaterial array with polarization-insensitive and wide-angle operating in triple-band (GSM 1800, WiMAX, WLAN). The cell of the array consists of four same Split-Ring Resonators arranged in rotating central symmetry. The structure and size of the metamaterial cell were analyzed and optimized by using the microwave simulation software of CST. Meantime, we studied the absorption efficiency and harvesting efficiency under the normal and oblique incidences, energy distribution on the cell and the surface current paths. The simulation results show that the harvesting efficiency is 30%, 90%, and 74% at 1.75 GHz, 3.8 GHz, and 5.4 GHz, respectively, on the conditions of random polarization and the normal incidence. When the oblique incidence changes from 0° to 45°, this meta-harvester can also maintain effective harvesting efficiencies in triple-band. A 7 × 7 array has been fabricated and measured, and a good agreement with the simulated results was obtained.