Asymmetric metasurface antenna with opposite currents for wide beam and low profile wide-angle scanning phased array

We propose a novel and simple method based on an efficient asymmetric metasurface antenna (AMSA) to achieve a low-profile phased array for wide-angle scanning. The designed AMSA is constructed by asymmetrically loading MS of spiral unit cells on one side of a compact parasitic patch antenna. Due to the proposed MS, two opposite current layers are induced on adjacent patches, which results in a wide beam pattern instead of the narrow beam of a conventional parasitic patch antenna. Based on the AMSA with a wide beam, a onedimensional phased array has been designed and simulated. The simulated results demonstrate that the AMSA phased array has a wide angle scanning range about ±70° and a low profile of 0.058λ. With the advantages of simple structure, no back cavity, no floor slotting, and low profile, the proposed novel method provides an efficient alternate for wide beam and wide-angle scanning.