A coding metasurface for reconfigurable multi-beams based on split I-shaped patch

In this paper, a type of reflective coding metasurface (MS) for reconfigurable multi-beams is proposed. The unit cell of MS is composed of a split I-shaped patch loaded with one varactor. By changing the bias voltage, the reflection phase of the unit cell can be adjusted in the range of 0°–180°. At the same time, vias are introduced between adjacent unit cells to restrain the coupling between unit cells and improve the scattering performance of the MS. The whole coding MS is composed of multiple “0” and “1” supercells. First, the supercell in which all the unit cells have same reflection phases of 0° or 180° is coded as “0” or “1.” By dynamically changing the coding sequence, reconfigurable dual beams are realized. Then, the unit cells with different reflection phases are employed to code the “0” or “1” supercell innovatively, and reconfigurable three beams are achieved. The results indicate that the regulated ranges of dual and three beams are θ = 5°–42° and 9°–42°, respectively.