Leaky-Wave Bessel-Beam Launchers: State of the Art and Future Trends

The generation of Bessel beams (BBs)—limited-diffraction, focused solutions of the Helmholtz equation—has recently attracted significant interest for applications in near-field communications, wireless power transfer, and imaging. Among the various technologies proposed for their synthesis, leaky-wave launchers stand out for their compact, low-profile, and single-feeder architectures. This paper provides the state of the art for this class of devices, systematically discussing the operating principles and design workflows for both resonant and wideband launchers. Moreover, this study establishes a reference framework for emerging research directions, with a specific focus on the practical performance of Bessel beams in radiative near-field scenarios.