Type:
Journal
Description:
We analyze and experimentally demonstrate the possibility of generating X-waves at microwave and millimeter-wave frequencies by means of a partially open radial parallel-plate waveguide antenna. The structure is azimuthally symmetric and fed in the center by means of a simple vertical coaxial probe, which excites a cylindrical leaky wave. Radially periodic annular slots etched in the upper metal plate allow the propagation of a backward leaky wave, as required for generating Bessel beams in the near-field region. Since X-waves are polychromatic superpositions of Bessel beams, the wavenumber frequency dispersion of the relevant leaky mode is accounted for by the antenna design. In particular, a dispersion-engineering approach is used to properly select the operating fractional bandwidth for the antenna. Even if the beneficial effect of a large bandwidth is partially neutralized by the dispersive character of …
Publisher:
AIP Publishing
Publication date:
1 Oct 2018
Biblio References:
Volume: 113 Issue: 14 Pages: 144102
Origin:
Applied Physics Letters