Broadband meta-surface with polarization-insensitive and wide-angle for electromagnetic energy harvesting

A novel metamaterial surface with polarization-insensitive and wide-angle operating in a broadband is presented. The metamaterial cell consists of four same e-shaped Split-Ring Resonators (SRRs) arranged in rotating central symmetry. The structure is analyzed and optimized by using CST software. The harvesting efficiencies on the normal and oblique incidences, energy distribution and the S parameters are also investigated. The simulation results show that the maximum harvesting efficiency is 92% at 5.4 GHz with the HPBW (Half Power Beam Width) of 54% (4.7GHz–8.2GHz) for the random polarizations under the normal incidence. On the oblique incidence of 60°, the maximum efficiency is 98.2% and 57.6% for TM and TE modes, respectively. The meta-surface has been fabricated and measured to verify the effectiveness of the broadband, polarization-insensitive and wide-angle energy harvester.