Folded Comb-Line Array for Backscattering-Based Bodycentric Communications in the 5G Sub-6 GHz Band

Growing interest in Internet of Things (IoT) and health care pushes the exploration of innovative solutions for connecting our bodies to external systems. The need for devices interoperability combined with data rate considerations, and low-power consumption make 5G backscattering-based communications a promising opportunity, especially in the low sub-6 GHz band. Starting from a monolithic array, this communication proposes a skin-mountable miniaturized antenna suitable for 3.6 GHz body-centric backscattering communications. The array is an improved version of the comb-line antenna, which simultaneously optimizes size and radiation features. The horizontal segments are folded such to place the radiating dipoles closer and increase the radiation efficiency of the structure by co-phasing a single component of the surface currents. Parametric analysis obtains optimal configurations in terms of gain and size. Compared to conventional layout, the miniaturized array has an efficiency 6 dB higher and an area 80% smaller while the improved structure provides a theoretical read distance of more than 4 m. Measurements on a volunteer corroborate the improved performance.