Flexible and Polarization-insensitive Metasurface Array for Microwave Power Transfer

In this work, a polarization-insensitive inkjet-printed metasurface(MS) array for microwave power transfer(MPT) is demonstrated. The substrate and conductors are separately based on Polyimide and liquid metal EGaIn. To solve the disadvantage that the conventional metasurface harvester needs to assign rectifier to each unit cell, a novel power combiner network to collect microwave power in different polarization directions is designed. The EBG structure is designed to reduce the coupling of the MS array. The trench etching on the transmission line is used to reduce the increased metal loss caused by the feeding network. The simulated results show that at 5.8 GHz, by adding EBG structure and trench etching operation, the harvesting efficiency(HE) is increased from 47% to 55%, and from 55% to 64%, respectively. The HE of polarized incident waves from 0° to 90° is more than 58%. The measured results show that the addition of EBG and the etching operation can improve the HE to 67% and the polarization-insensitivity can be maintained under multiple conformal degrees.