Design of a dual-mode operation 2-D periodic planar leaky-wave Antenna
In this contribution, we describe the design and the radiation features of a dual-mode operation low-profile, low-cost, wideband antenna. The structure is made by an annular, 2-D radially periodic, leaky-wave antenna enabling the generation of both high-gain beams in the far-field and of nondiffracting waves within the near-field radiative region. This is obtained through the generation of a fast backward spatial harmonic supported by a metal-strip grating placed on a grounded dielectric slab.