Innovative systems based on optical nanoantennas for energy harvesting application

The purpose of this study is to outline the main guidelines for the design of arrays of optical rectennas aiming to harvest energy and for the optimization of the power transfer to an external load. In particular, the novelty of this study consists in introducing the concept of the integrated design between the array of optical rectennas and the harvesting circuit able to exploit the available energy. The design of the array represents the crucial point in order to optimize the power transfer between the antenna and the load and can influence the rectenna design. On the other hand, the maximum power transfer to the load has to be obtained under matching conditions between the array and the load and can influence both the design of the array and of the converter to supply a load. A previous study of the main type of nanoantennas and their relative structures will be fulfilled in order to choose the particular structure, which will be analysed in this work. Therefore, a numerical analysis of the chosen structure, a dipole nanoantenna, and a description of the rectenna topology will be performed. The exploitation of the available energy requires the use of the DC-DC boost converter, which allows to interface a rectenna system with a downstream load. The choice of the commercially DC-DC boost converter will allows to design an array of optical rectennas in order to achieve the impedance matching conditions to a harvesting circuit. Finally, since the equivalent impedance of the array of optical rectennas changes with the solar radiation during a day, the optimization of the maximum power transfer between the array and the harvesting circuit will be investigated.