Ku-Band Low-Profile Dual-Circularly Polarized Planar Reflectarray

In this letter, a dual circularly polarized planar reflectarray antenna suitable for Ku-band satellite communication was proposed. The array adopts a single layer metasurface structure, and the unit cells are primarily composed of hexagonal metal splitted rings with different sizes. By synthesizing Berry phase and Dynamic phase, the independent control of left-hand circularly polarized (LHCP) and right-hand circularly polarized (RHCP) double beams is realized. The bandwidth of the designed cells is 28% (10.5 GHz - 14 GHz) with a reflection coefficient amplitude greater than -1dB. When a left-handed circularly polarized wave at the center frequency (11.725 GHz) excites the array, the beam direction of the antenna is <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\boldsymbol{\varphi},\boldsymbol{\theta}) =(\mathbf{90}^{\circ},-\mathbf{20}^{\circ }))$</tex>, the maximum gain reaches 27.7 dB, the aperture efficiency is 48.3%, and the 1 dB gain bandwidth is 37% (11 GHz to 16 GHz). When a Reft-handed circularly polarized wave excites the array, the above performance parameters are (90°, 20°),27.8 dB, 49.5% and 34%, respectively.