Omnidirectional metasurface 2-D leaky-wave antennas with full polarization reconfigurability

Fabry-Perot cavity antennas with polarization-reconfigurable omnidirectional conical beams are presented. The partially reflecting screen covering the antenna cavity is constituted by omnidirectional homogenized metasurfaces exhibiting rotationally invariant electromagnetic features, and specifically metal patterned screens are considered. The antenna operates on the first higher-order TMi and TEi leaky modes, whose phase and attenuation constants are properly equalized. Undesired radiation from the fundamental quasi-TEM mode is avoided by suitably loading the cavity with a dielectric or wire-medium slab. The independent excitation of such TM₁ and TE₁ leaky modes, with a pair of azimuthally-independent sources, is shown to give rise to omnidirectional scanned beams with full polarization reconfigurability. 2-D leaky-wave antennas with a circularly-polarized conical beam are presented, which confirm the effectiveness of the proposed design.