Broadband polarisation-independent metasurface electromagnetic energy harvester with high capture efficiency

This study presents a broadband metasurface harvester with polarisation-insensitive and high harvesting efficiency. The proposed metasurface constitutive main cell consists of two intertwined modified inner and outer Jerusalem cells with two combined different resonance frequencies to obtain a broadband bandwidth. The parameters of the proposed cell are optimised to capture the energy of ambient electromagnetic waves with the least possible return loss and deliver it to the resistive loads through optimally positioned vias. The optimum load resistance value for the proposed harvester is 100 Omega. The simulation results obtained from CST Microwave Studio solver show relative band width of 18% from 8.75 to 10.5 GHz for different polarisation angles under a normal incident plane wave. Finally, an array of 8 x 8 cells of the proposed harvester has been fabricated and its electromagnetic properties have been measured which show good agreement with the simulation results.