A Wideband Quad-Polarization Reconfigurable Metasurface Antenna

Abstract

A low-profile wideband metasurface antenna with quad-polarization reconfiguration ability is presented in this paper. The proposed metasurface antenna is composed of a square patch, a metasurface formed by a lattice of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4 \times 4$ </tex-math></inline-formula> periodic metal plates, and four switchable feeding probes connected with two designed single-pole double-throws switches. By properly selecting the feeding probes, the polarization of the metasurface antenna can be dynamically reconfigured among four polarization states, i.e., <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$x$ </tex-math></inline-formula> -direction linear polarization, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$y$ </tex-math></inline-formula> -direction linear polarization, left-hand circular polarization, and right-hand circular polarization. To validate the proposed concept, a prototype operating at 5.6 GHz with a relatively height of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.067~\lambda _{0}$ </tex-math></inline-formula> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda _{0}$ </tex-math></inline-formula> is the operating wavelength in free space) is designed, fabricated, and measured. The measured results show that both the 10-dB impedance bandwidths and the 3-dB axial ratio bandwidths are wider than 5.1–6.0 GHz for the linear and circular polarization states. The measured maximum gains are 9.39 dBic and 9.85 dBi for the circular polarization states and the linear polarization states, respectively. The simulation and experimentation verify that the proposed antenna can achieve quad-polarization reconfigurable features in a wide frequency band, which indicate the good performance of the proposed polarization reconfigurable metasurface antenna.