Graphene Materials for Total Efficiency Enhancement of Electrically Small Antennas

Electrically small antennas (ESAs) suffer from low total efficiency due to severe impedance mismatch. Traditional metallic ESAs exhibit extremely low real part of the input impedance, making efficient impedance matching challenging. This paper proposes leveraging the high real part of the input impedance of graphene antenna to overcome this limitation. A dual-arm dipole antenna model is constructed for theoretical analysis, and electromagnetic field simulations. The simulated results show that a graphene-based dipole ESA with a length of 1/29 wavelength (at an operating frequency of 1 GHz) achieves a total efficiency of 1.29%, representing a 11.2% improvement over a copper-based ESA with the same structure (1.16%). The impedance matching efficiency increases from 1.33% to 2.25%. This study demonstrates that the superior impedance matching efficiency of graphene-based ESAs can compensate for their lower radiation efficiency, providing a new approach for optimizing the total efficiency of electrically small antennas.