Beam Steering Microstrip Antenna Using an Agile Spherical Cap Metamaterial Lens

The goal of this work is to design beam-steering antennas, for which it is possible to control the antenna radiation pattern using an agile spherical cap metamaterial lens. For this purpose, we design an agile metamaterial unit cell which can flip between two different states. Depending on the unit cell state, the metamaterial behaves has a refractive index close to zero (n similar to 0) in the first case, and greater than unity (n>1) in the second one. An external control system allows us to program the metamaterial behavior by acting on each unit cell individually. The half power beam width of the antenna in the E and H planes is about 23 degrees and 19 degrees, respectively, and can be rotated by about 33 degrees in the E-plane and 36 degrees in the H-plane, in both side of the central direction. The used agile metamaterial lens also enhances the microstrip antenna realized gain. The maximum realized gain obtained is 12.69 dB.