Future scenarios of wireless communication systems, in particular the envisioned 5G mobile network, call for technological advances enabling higher data rates, higher densities of users, device-to-device communications, as well as wireless power transfer.
In this framework, the proposed research aims at the analysis and design of novel planar radiators operating at microwave, millimeter-wave, and terahertz frequencies and based on the excitation of cylindrical leaky waves (i.e., of two-dimensional leaky-wave antennas, 2D LWAs), characterized by radiative features beyond the state of the art for this class of antennas. In particular, the focus will be on the synthesis of i) wideband directive broadside beams; ii) fixed-frequency, angle-reconfigurable conical beams; iii) focused radiation with non-zero orbital angular momentum (OAM) via backward leaky waves with higher azimuthal order.
Azimuthally symmetric 2D LWAs will be considered, based on a partially reflecting surface (PRS) constituted by an array of concentric ring slots placed on top of a suitable dielectric multilayer. The key design elements for achieving the desired radiative properties will be: the geometry of the radially-modulated PRS, possibly realized with graphene to achieve reconfigurability via electrostatic bias; the number and type of layers in the multilayer background structure; the unconventional lateral truncation of the antenna; the development of novel feeding structures aimed at imparting the desired azimuthal standing- or traveling-wave character to the relevant leaky waves.
The designs will be crucially based on accurate modal characterizations of the waves traveling radially along the considered antennas and will be validated through full-wave numerical simulations as well as through the realization of antenna prototypes and their experimental characterization.
