Omnidirectional 2-D Leaky-Wave Antennas With Reconfigurable Polarization

Fabry–Perot cavity two-dimensional leaky-wave antennas with polarization-reconfigurable omnidirectional conical beam are proposed. The antenna cavity is bounded by an annular, locally periodic metal partially reflective surface, and is loaded by a dielectric or a wire-medium slab in order to suppress undesired radiation from the fundamental quasi-TEM mode. A suitable design of the partially reflective surface and of the loading slab, based on a dispersion analysis of the linearized structure, allows for equalizing the phase and attenuation constants of the first higher order TM<inline-formula><tex-math notation="LaTeX">$_1$</tex-math></inline-formula> and TE<inline-formula> <tex-math notation="LaTeX">$_1$</tex-math></inline-formula> leaky modes around a given frequency. Omnidirectional beams with full polarization reconfigurability are then achieved through independent excitation of such modes with a pair of azimuthally independent sources. Preliminary designs, aimed at producing a conical beam with circular polarization, are presented and optimized with state-of-art simulation software.