A phased-array antenna assembly includes an antenna board stack, a radome configured to cover the antenna board stack, and a casing configured to support the antenna board stack. The antenna board stack includes a central core, a bottom antenna unit defining a bottom thickness between a bottom surface of the central core and a bottom end of the antenna board stack, and a top antenna unit defining a top thickness between a top surface of the central core and the top end of the antenna board stack that is substantially equal to the bottom thickness. The bottom antenna unit includes two spaced apart bottom metal layers each associated with a different distance from the axis of symmetry. The top antenna unit includes two spaced apart top metal layers each associated with a corresponding one of the distances from the axis of symmetry associated with the bottom metal layers.