Optimization of thermal deformation of ultrahigh frequency remote sensing reflector and manufacture of a zero-expansion composite

Space ultrahigh frequency remote sensing reflectors (above 600 GHz in operating frequency range) will cause thermal deformation problems due to non-uniform spatial temperature changes during orbital operation. In order to ensure the electrical performance of the reflecting surface, the space ultrahigh frequency remote sensing reflector requires the surface accuracy of the reflecting surface to have a root mean square of r ≤ 10 μm. Therefore, a novel single-panel grid structure reflector was innovatively proposed, and the thermal deformation analysis of the reflector was performed using finite element analysis software. The influence of different structural parameters of the reflector on the thermal deformation of the reflector was studied, and the structural parameters of the reflector were optimized based on the principle of low thermal deformation. The optimized results still couldn't meet the surface accuracy requirements of space ultrahigh frequency remote sensing reflectors. Therefore, a zero-expansion composite with coefficient of thermal expansion α ≤ 0.5×10^-7℃^-1 was designed and manufactured. The zero-expansion composite is combined with carbon fiber reinforced polymer composites (CFRP) and Kevlar fiber fabric interlaced and layered in a certain ratio. By adjusting the ratio of reflecting surface laminates, the thermal deformation of the reflecting surface can be reduced to 7.94 μm to meet the surface accuracy requirements of ultrahigh frequency remote sensing reflector.