High-Efficiency and Flexible Inkjet-Printed Quasi Metasurface Harvester for Microwave Power Transfer Application

This letter demonstrates an inkjet-printed quasi metasurface (QMS) flexible harvester for microwave power transfer (MPT). The substrate and radiator are separately based on polyimide and Eutectic gallium indium alloy (EGaIn), in which the mass fraction of Ga and In are 75.5% and 24.5%, respectively). Due to the high electromagnetic energy loss of flexible materials, the electric field distribution is improved by etching on the transmission structure; consequently, the energy loss of the material is reduced. The simulated results show that under vertical incidence at 5.8 GHz by trench etching operation, the absorption efficiency and harvesting efficiency (HE) are both increased from 93% and 65% to 99% and 82%, respectively. The measured results show that the maximum HE is up to 78%, more than 60% HE can be maintained under multiangle incident waves and more than 70% HE can be maintained in different conformal cases.