In various embodiments, an antenna array may comprise a dielectric; a first patch antenna disposed on a first region of the dielectric; a second patch antenna disposed on a second region of the dielectric; and a ground layer including a first sub-ground layer in contact with a lower portion of the first region of the dielectric, a third sub-ground layer in contact with a lower portion of the second region of the dielectric, and a second sub-ground layer spaced apart from a lower portion between the first region and the second region of the dielectric.