PRELOADED PARABOLIC DISH ANTENNA AND THE METHOD OF MAKING IT

摘要

The back-up structure of a parabolic dish antenna, which supports its reflecting surface, is formed in this invention by preloading its radial and circumferentially placed straight structural members and hence it is termed as preloaded parabolic dish antenna. Such a preloading results in considerable reduction in its weight and also to the effort involved in its assembly. The back-up structure of the preloaded parabolic dish antenna is made of a central hub, an assembly of a suitable number of elastically bent radial structural members connected rigidly to the central hub and to the same number of straight structural members which are connected to the tips of the radial members at the outer rim of the dish and also to straight bracing members placed circumferentially at intermediate locations, which are all tensioned to specified prestress values in the absence of wind loading. The outermost rim members placed at the periphery of the dish form the aperture of the dish. The back-up structure of the preloaded parabolic dish anntenna is given the parabolic shape by fixing the radial members at a suitable inclination angle and location at the hub and by applying an appropriate force with a normal component at their tips so as to bend the radial members elastically such that their curvature becomes approximately the same as that of the parabolic curve between the hub and the peripheral rim point.