A dual-band, wide-angle absorbing metasurface for EM energy harvesting and wireless power transfer

Abstract

In this paper, a dual-band metasurface is designed for electromagnetic (EM) applications in the sub-6G band. The metasurface consists of a hexagonal Complementary Split Ring Resonator (CSRR) absorber array, a dual-band impedance-matched rectifier network, and a load. The CSRR metasurface absorber is designed by combining a hexagonal prism and a hexagonal ring. The proposed absorber is surrounded by metal vias to improve the operating stability of each cell. By integrating the absorber array with the rectification network, the system redundancy and power loss are reduced. The designed metasurface is capable of harvesting EM energy in different frequencies using one port, even at a wide incidence angle. Dual-band rectification within the Sub-6G range is achieved by the rectification network at low input power density. We fabricated and measured a 3 × 3 hexagonal CSRR metasurface array, and the experimental result shows that the optimal input power is 2 dBm (the incident power density is 169 μW/cm2), the radio frequency(RF)-to-direct current(DC) efficiencies are 57.6% and 47% at 3.8 and 5.2 GHz, respectively.