Twin-grid array as 3.6 GHz epidermal antenna for potential backscattering 5G communication

Emerging 5G infrastructures can boost innovative paradigms for future wearable and epidermal devices exploiting low-power (even passive) wireless backscattering-based communication. To compensate high body and path losses, and to extend the read range, array configurations are required. This letter proposes a flexible monolithic epidermal layout, based on the Krauss array concept, that operates at 3.6 GHz, and it is suitable to be directly attached to the human body. The antenna involves a dual-grid configuration with a main radiating grid backed by a grid reflector placed in touch with the skin. Overall, the number of conductors and dielectric substrates is minimized with benefit to breathability. The antenna is suitable for surface feeding and produces a broadside radiation. Parametric analysis is performed, and an optimal configuration of a four-cell grid is derived and experimentally demonstrated to provide a maximum gain of more than 6 dBi.