A Dipole with Reflector-Backed Active Metasurface for Linear-to-Circular Polarization Reconfigurability

In recent years, significant advances have been made in diversifying the capabilities of communication systems by using reconfigurable antennas. There are many types of reconfigurable antennas-to achieve pattern, frequency, or polarization reconfigurability. These antennas are reconfigured either by the mechanical rotation of surfaces or by enabling or disabling specific sections of the structure using electrical switches. This paper focuses on the concept of a polarization reconfigurable antenna based on an active reflector-backed metasurface. An antenna system based on an active reflector-backed metasurface combined with a planar dipole is designed to achieve reconfigurable polarization. The polarization of the designed antenna can be switched between linear and circular polarization states using positive-intrinsic-negative diodes located in the unit cell elements of the metasurface. The measured results correlate well with the simulated results. The antenna has a physical size of 308 × 162 × 35 mm³ with an impedance bandwidth of 4.5% in the linear state and 7% in the circular state, as well as an axial ratio bandwidth larger than 8.3%.