Beam Steering Patch Antenna Array Using Reconfigurable Patch

In this letter, reconfigurable parasitical patches are used to design the beam steering patch antenna array. The designed beam-steerable antenna array is composed of two fixed patches and two reconfigurable parasitic patches. The reconfigurable parasitic patch is made up of two rectangular patches and a varactor diode. By changing the capacitance value of the varactor diode, the impedance of the parasitic patch is changed, which affects the parasitic patch's current phase and antenna beam direction. Stable impedance matching under different capacitance values can be achieved without additional structure. An antenna array is designed and fabricated to verify the proposed method. The beam-steerable angles of the simulated and measured results are ±30° and ±27°, respectively.