Structural Design And Analysis Of Singlecone Antenna For Spaceborne All-space Spectrum Measurement

"Hongmeng Project" ultra-long wave radio astronomical observation array will detect the global spectrum 21 cm signal in lunar orbit for the study of the early evolution of the universe.According to the requirements of the "Hongmeng Project",the structural design and analysis of the single cone antenna on board the radio array unit are carried out in this paper.Based on the analysis of the performance requirements of the single cone antenna,the main technical specifications of the antenna structure are defined.The overall scheme of the single cone antenna body,drive selection and antenna turntable is proposed.The key technologies and difficulties of the high convergence rate,structural simplicity and reliability of the single cone antenna are also analysed.Five types of deployment mechanism are proposed according to the requirements of the deployment function of the single cone antenna on board,and through comparison and analysis,the parallel folding link support deployment mechanism is selected to achieve the design goal of 90.01% axial collapse rate.The dynamics analysis model of the deployment mechanism of the single cone antenna on board is established,and the dynamics simulation analysis of the deployment mechanism under two working conditions in orbit and on the ground is carried out to optimise the drive arrangement and drive force of the deployment mechanism.The results show that the maximum stress of the support rod during the unfolding motion is 110.6 MPa,which is less than the allowable stress of the material.Through the linear buckling simulation analysis,it is verified that the antenna body film has the ability to maintain the original sructure shape in the unfolded state.A thermal analysis model of the single cone antenna body on board is established,and the thermal stability analysis of the material and thermal control factors under two types of extreme temperature conditions in near-moon orbit is carried out.The results show that for the same thermal control coating,the CFRP material has a 30.99% reduction in maximum temperature,72.25% reduction in thermo-deformation and 52.82%reduction in thermal stress compared to PTFE at extreme high temperature conditions.For the same satellite thermal power,the CFRP material has a 44.27% increase in maximum temperature compared to PTFE at extreme low temperatures.Thermal deformation is reduced by 37.09%.The prototype of the antenna parallel telescopic rod support deployment mechanism is fabricated and commissioned.Through experimental measurements of the prototype unfolding,the prototype achieved a 89.71% take-up rate,achieving the desired design goal.The unfolding process of the unfolding mechanism is tested and the results showed that the unfolding mechanism could be unfolded smoothly without interference,and the four parallel telescopic support rods are well synchronised with each other.And the unfolding times for each group of different driving arrangements are 270.95 ms,227.22 ms,236.97 ms and 136.28 ms respectively,which are in good agreement with the mechanism dynamics simulation.The ability of the film to maintain its original structure shape is verified through the linear buckling test of the copper ducted film.The design and analysis of the single cone antenna body deployment mechanism,the design of the antenna turntable and the fabrication and testing of the prototype deployment structure in this paper provide a solution for the engineering design of the satellite antenna structure of "Hongseng Project" and will promote the advancement of the project and its technological development.