High-Transmission Ultrathin Huygens’ Metasurface with 360° Phase Control by Using Double-Layer Transmitarray Elements

Metasurfaces (two-dimensional metamaterials) have attracted much attention in recent years. However, due to the symmetric design of its cascaded elements, a traditional transmission-type metasurface must be at least three layers thick to achieve high transmission and 360\ifmmode^\circ\else\textdegree\fi{} phase control simultaneously. This study presents an ultrathin Huygens' metasurface, composed of double-layer antisymmetric transmitarray elements, that can realize high transmission and 360\ifmmode^\circ\else\textdegree\fi{} phase control at once. Based on this metasurface, a high-gain ultrathin (3.3% of the wavelength) transmitarray antenna is created, with an aperture efficiency of 61.04% at the working frequency.