Design Methods for Dual Polarized Metasurface Antennas: Three Simple Approaches

Metasurface (MTS) antennas are based on the transformation of a cylindrical-wavefront surface wave (SW) into general wavefront leaky (LW). The MTS aperture is constituted by grounded dielectric slab printed with an electrically dense distribution subwavelength patches realizing space-variable, homogenized tensor impedance boundary conditions (IBCs). One challenges in this type antenna related to obtaining dual polarization operations using same modulation. In article, we explore and compare three simple approaches obtain two beams orthogonal polarizations feeding ports. A first known method exciting both transverse electric (TE) magnetic (TM) SW mode modulated impedance. second exploits concept modulation sharing, according which distinct modulations, designed radiate different when properly illuminated offset points, superimposed aperture. third consists duplexing outward (radially diverging) inward (converging center) SW. Simple analytical formulas presented for synthesis that allows control inward/outward waves ensure balanced radiation performances terms efficiency polarizations. comparison between latter presented.