Design of Tunable Graphene Nano-Antenna for Energy Harvesting Applications

The goal of this paper is to design tunable nano-antennas using graphene for energy harvesting. A metal-semiconductor-metal-two-dimensional electron gas varactor diode enables the tuning of the nano-antenna's frequency, while the positioning of graphene allows steering the antenna's radiation to different locations. This work offers several benefits, such as the ability to use the nano-antenna in various applications, including the fifth-generation wireless networks. The results show that the standalone nano-antenna achieves a maximum gain of 4.82 dB with a bandwidth of 4.69%. While the copper-based metamaterial lens offers a slight gain improvement to 4.94 dB, it reduces the bandwidth to 4.02%. Crucially, this study reveals the ability of strategically positioned graphene within the lens to steer the radiation pattern. Positioning the graphene at specific locations (P1, P2, or P5) rotates the main lobe by ~15 deg. Conversely, placing the graphene between other positions (P3, P4, or P6) steers the beam by -10 deg.