Fractal Graphene Patch Antennas and the THz Communications Revolution

Fractal antennas have and are continuing to receive attention in regard to the future of wireless communications. This is because of their wide- and multi-band capabilities, the opportunity of fractal geometries to drive multiple resonances, and, the ability to make smaller and lighter antennas with fewer components and radiative elements with higher gains. Small scale (i.e. on the micro- and nano-scale) and ultra high frequency (in the Terahertz or THz range) fractal antennas composed of Graphene have the potential to enhance wireless communications at a data rate that is unprecedented, i.e. ∼ 10¹² bits per second. A Fractal Graphene antenna is a high-frequency tuneable antenna for radio communications in the THz spectrum, enabling unique applications such as wireless nano-networks. This is because (mono-layer) Graphene is a one-atom-thick two-dimensional allotrope of Carbon with the highest known electrical conductivity that is currently unavailable in any other material, including metals such as Gold and Silver. Thus, combining the properties of Graphene with the self-affine characteristics of a fractal at the micro- and nano-scale, provides the potential to revolutionise communications, at least in the near field (the order of a few metres) for low power systems. In this paper, we consider the basic physics and some of the principle mathematical models associated with the development of this new disruptive technology in order to provide a guide to those engaged in current and future research, a fractal Graphene antenna being an example of an advanced material for demanding applications. This includes some example simulations on the THz field patterns generated by a fractal patch antenna composed of Graphene whose conductivity is taken to scale with the inverse of the frequency according to a ‘Drude’ model. The approach to generating THz sources using Graphene is also explored based on Infrared laser pumping to induce a THz photo-current.