Recent advances in leaky-wave antennas: From far-field to near-field applications

Leaky-wave theory has fruitfully been exploited since many decades to design a class of frequency-scanning microwave antennas and arrays. In the last years, the role of leaky waves in the ecient description of radiation phenomena has proven to be an advantageous means to realize further innovative antenna functionalities. These functionalities involve features useful for various recent appealing applications (5-G communications, wireless power transfer, etc.), such as far-field pattern and polarization reconfigurability, wideband broadside radiation, as well as near-field limited-diractive beam focusing. The research advances in these contexts are reported here, with specific attention to planar leakywave radiators operating in microwave, millimeter-wave, and terahertz ranges