Novel two-dimensional radio frequency energy harvesting system: Design and implementation

Recently, numerous published research studies and projects have focused on designing a passive charger for earphones and mobile phones. Such studies depend on a one-dimensional (1D) voltage multiplier circuit using a Schottky diode. To increase the harvested power, this study presents a novel two-dimensional (2D) radio frequency (RF) energy harvesting system based on a wideband microstrip antenna. The fabrication and design analysis of the 2D-RF n-stage voltage multiplier circuit using a zero-biasing Schottky diode are carried out. The design of this 2D-RF energy harvester is based on the idea of multi-RF current source passive energy harvesters that feed only one load through the main n-stage voltage multiplier circuit to increase the load current and consequently the power delivered to this load. This circuit was fabricated using a 10.4 relative permittivity FR4 substrate. In addition, the matching between the RF antenna output and the input of the 2D-RF voltage multiplier circuit was considered in the design analysis and fabrication to prevent RF power reflection. The circuit was simulated using ORCAD 9.1, and the simulation results were investigated at different frequencies and values of load resistance. In addition, the experimental results of the prototype model are compared with those of earlier related work. Finally, the results proved that the output power delivered from the proposed 2D system is approximately equal to that delivered by the 1D system multiplied by the number of RF voltage multiplier circuit stages 100 cm away from the RF source.