An antenna made up of addressable conductive segments, or pixel elements, affixed to the top of each piston in a piston array is presented. The pixel elements can be activated in less than a millisecond to form an antenna array and transmission line pattern using movable pistons and a two-dimensional actuator. Each piston comprises a handle, a bottom conductive segment affixed to the top of the handle, a dielectric segment affixed to the uppermost surface of the bottom conductive segment, and a top conductive segment affixed to the uppermost surface of the dielectric segment. When the piston is not actuated, the top conductive segment forms part of a ground plane. The top conductive segment form part of the transmission line and antenna array patterns, the dielectric segment becomes a dielectric space and the bottom conductive segment forms part of the ground plane when the piston is actuated.