Co-Location of PV Panel With Meshed Antenna Array for Inter-Satellite Energy Transmission

This paper investigates the design and fabrication, by additive manufacturing, of optically transparent meshed patch antenna arrays atop photovoltaic (PV) panels. This integration is foreseen to be exploited in space by small satellites to enable wireless power transfer among them, while maintaining optimal solar power production, with no need for extra areas for the antenna subsystems. The proposed antenna arrays utilize a novel approach, where horizontal conductive strips of a meshed metallization are removed, to enhance transparency without compromising antenna performance. Two arrays are designed at 2.45 GHz and 5.8 GHz, and the associated design choices and issues are discussed. The antenna metallizations make use of vertical strips only with a line spacing of 0.04 lambda, found to be the best compromise to ensure maximal transparency and antenna performance, using low-cost printing technique on 110 mm X 110 mm borosilicate glass. Simulations and experiments show that the underlying PV metallization patterns have a significant impact on the antenna radiation properties at the highest operating frequency of 5.8 GHz. In this case, a degradation of the antenna gain compared to the predictions is observed. Through a reverse-engineering method, this effect is modeled by the effective electromagnetic characteristics of the glass substrate, rather than by accounting for the pattern layout-wise. It is demonstrated that this choice enables an efficient yet accurate full-wave simulation of the entire system, suggesting the necessity for a co-design of the PV panel and the antenna to facilitate an accurate representation of the entire system and its current radiating characteristics.