Innovative Application Contexts for Focusing Devices based on Leaky Waves

Nowadays, there exist many kinds of devices capable to generate focused electromagnetic radiation with reduced diffraction in the near field, such as Bessel beams. Among them, those based on leaky waves, also known as Bessel-beam launchers (BBLs), have attracted much attention thanks to their low-profile, low-cost, and design flexibility. While the design rules of different kinds of BBLs have been already presented in the literature, their performance when used for transmitting either power or information is scarcely reported. The aim of this work is to comprehensively review and explain their implementation and design principles through a simple, analytical, yet effective leaky-wave approach. Furthermore, their performance in wireless power transfer scenarios is reported showing promising results. Finally, their potential use in secure near-field point-to-point communications is investigated, thus paving the way for future research and development in this rapidly evolving area.