Ultra Thin Deployable Reflector Antennas

We have recently proposed a new concept for deployable reflectors consisting of a thin parabolic carbon-fibre-reinforced-plastic (CFRP) shell stiffened along the edge by an elastically collapsible stiffener. Here we show that a stiffener accounting for less than 10% of the total mass of the reflector increases the stiffness of the softest deformation mode of the deployed reflector by 48 times, and its fundamental natural frequency of vibration by 6.8 times. These values are based on an optimized design of the stiffener, for a 4.6 m diameter paraboloidal reflector with focal length-to-diameter ratio of 0.28, which is detailed in the paper. Residual cooling stresses from the manufacturing process often induce relatively large distortions in thin CFRP structures – potentially reducing their surface accuracy. It is shown by analysis that these distortions are reduced by a factor of 100 in the proposed stiffened reflector.