Metamaterial electromagnetic energy harvester with near unity efficiency

We present the design of a metamaterial medium for electromagnetic energy harvesting based on the full absorption concept. A metamaterial slab was designed comprising 13 × 13 electrically small cells, each loaded with an 82 Ω resistor which mimics the input impedance of a rectification circuitry. Unlike earlier designs of metamaterial absorbers, here the power absorption is mostly dissipated across a resistive load instead of the dielectric substrate. This implies that effective electromagnetic energy harvesting can be achieved. The power is channeled through a via connected to each cell. For a design optimized at 3 GHz, simulation and experimental results show power absorption efficiency of 97% and 93%, respectively.