A novel Hexagonal Excitation for a Multi-Layer Wearable Miniaturized Antenna

Microstrip antennas are widely used for Wireless Power Transfer applications both in medical and industrial environment, however, a trade-off between performance and dimensions must be set. This article proposes an hexagonal rectenna with enhanced radiation performance. The two-layer structure accounts for an hexagonal ring antenna equipped with concentric parasitic rings, fed by a microstrip line that couples with the antenna parasitic elements in order to achieve optimum matching conditions at 2.45 GHz. The second layer, made by metallized FR-4, allows for enhancing the radiation performance of the overall structure reaching for a 20 % and more than a +1.5 dBi increment in the antenna radiation efficiency and gain respectively, while maintaining overall small dimensions.