Rectifying Metasurface With High Efficiency at Low Power for 2.45 GHz Band

This letter presents a novel rectifying metasurface with high efficiency at low power applicable to wireless power transfer and energy harvesting. The proposed rectifying metasurface is a two-sided structure consisting of modified electric-inductive-capacitive unit cells on one side and a rectifying circuitry on the other, designed to resonate and rectify at 2.45 GHz. Each unit cell is directly connected to a voltage-doubler rectifier, allowing the incident microwaves to be directly rectified upon reception. The impedance characteristics and rectification performance of the proposed rectifying metasurface are tested via numerical simulation and measurement, respectively. The measured results demonstrate an overall conversion efficiency (electromagnetic power absorption + rectification) of 76.8% at 0.4 dBm incident power.