Methods of fabricating air-filled true-time-delay, continuous transverse stub array antenna. A plurality of extruded sections that are physically independent of one another are fabricated. The plurality of extruded sections are arranged in a predefined pattern defining the structure of the array antenna. Adjacent surfaces of the extruded sections form waveguides of the array antenna. The plurality of extruded sections are joined together at their respective ends to form the array antenna. The plurality of extruded sections may be joined using a plurality of end plates. The plurality of extruded sections and end plates may comprise metal or plastic. If the extruded sections are plastic, they are metallized (44) using a process such as vacuum deposition, electroless plating, or lamination during the extrusion process. The end plates are sealed to the extruded sections to form the array antenna structure.