A Dual-Band, Polarization Insensitive Rectifying Surface for RF Energy Harvesting

A dual-band polarization-insensitive metasurface array-based RF energy harvester is presented in this paper. The unit cell of the metasurface consists of an X-shaped and four Dshaped slotted resonators. 4 Schottky diodes (BAT15-03WL) are embedded in the rectifying surface. A simultaneous impedance matching between free space and rectifying surface (metasurface + rectifier diodes) is achieved at 3.035 GHz and 6.885 GHz. The unit cells are connected with thin highly inductive microstrip lines to collect DC voltage. The proposed RF energy harvester offers more than 95% absorption efficiency for different angles of polarization and up to 80% absorption efficiency for wide angles of incidence at both the designated bands. The proposed harvester can harvest energy from the 3.035 GHz and 6.885 GHz frequency bands.