A Further Realization of a Flexible Metamaterial-Based Antenna on Nickel Oxide Polymerized Palm Fiber Substrates for RF Energy Harvesting

This paper discusses the design of a low-profile Hilbert-shaped metamaterial (MTM) array-based printed circuit antenna forming a rectangular patch and backed by a partial ground plane; the rest of which is loaded with a square Electromagnetic Band Gap (EBG) structure for RF energy harvesting. The antenna is mounted on a 28 mm × 32 mm nickel oxide polymerized palm fiber (INP) substrate and compared to the identical one based FR4 substrate. The two prototypes are printed with silver nanoparticles (SNP). The antenna performance is tested numerically and experimentally in terms of S₁₁ and radiation patterns. The obtained antenna gain bandwidth product of the INP prototype is found significantly better than the FR4 prototype. The proposed INP antenna gain at 5.8 GHz and 8 GHz frequencies are found about 4.56dBi and 7.38dBi, respectively. While, the FR4 antenna gain is found 4.56dBi and 6.85dBi at 5.8 GHz and 8 GHz, respectively. Finally, the collected output DC voltage and the conversion efficiency from the harvested RF energy are measured experimentally at 5.8 GHz and 8 GHz for both proposed prototypes.