A high gain antenna system with polarization and pattern diversities by employing reconfigurable metasurface

In this paper, a two-dimensional array composed of uniform metal strips is proposed for the design of reconfigurable metasurface. Five metal strips distributed along the x -axis are connected in series by PIN diodes to form one-dimensional metasurface cell distributed along the y -axis. By dynamically adjusting the working state of the PIN diodes, a non-uniform metasurface array composed of two-dimensional array and one-dimensional array can be obtained. Attribute to the difference in phase and reflection coefficient between the two types of metasurface arrays, the characteristic of beam direction being able to twist is achieved. Based on the reconfigurable metasurface, a polarized reconfigurable antenna is designed, which improves the flexibility of the antenna system in terms of polarization and radiation characteristics. Experimental results consistent with theoretical analysis indicate that the proposed metasurface exhibit excellent gain enhancement and pattern transformation characteristics for both patch antenna and reconfigurable antenna. In detail, for the designed antenna system, up to nine operating states are achieved within the resonant bandwidth of 4.41–4.56 GHz. Among them, the linearly polarized and circularly polarized radiation modes with maximum gains of 11.03 dBi and 9.82 dBic respectively show diverse radiation patterns and radiation efficiencies higher than 76.6%, which is an effective solution for the increasingly complex communication environment and diversity requirements of users.