Reflectors or antenna reflectors are used in outer space for communication purposes. They have a surface which follows the contour of a hyperbola or parabola. Accordingly, they have a double-curved surface. Effective and accurate operation requires that the surface have a substantially exact curvature.
Conventional reflectors have a netting or a network structure of composite fiber material as the reflector surface. In a conventional procedure, the reflector surface is fabricated by laying a thread in such a way as to produce a network structure. The laying of the thread is effected on a flat support, for example, by a thread laying robot. Next, the preliminary structure is transferred to the desired contour surface, for example, a parabolic surface which has a double curvature.
The known manufacturing method, however, has the drawback that a deformation of the structure occurs when the preliminary structure is transferred from a planar support or from a single-curved support, such as a winding spindle, to the double-curved contour surface. Furthermore, stresses are induced in the structure and the network surface becomes distorted. The network structure is also distorted or deformed when the network structure is first fabricated on a winding spindle and then transferred to the contour surface. Therefore, the reflector surfaces produced by the conventional manufacturing processes have an imprecise contour, which deviates from the ideal shape. In addition, surface imperfections such as dents or the like may arise from stresses in the reflector surface.
Furthermore, especially in the case of reflectors which are folded for purpose of transport into orbit and deployed upon reaching their station in outer space, the problem arises that additional stresses are induced by virtue of differing degrees of curvature in different regions of the deployed reflector surface. This contributes to further distortion of the network surface, especially when in use over a long time.
USPTO Backgrounds
USPTO Backgrounds