Study On Mechanical System Design Of Weighty Payload And High Accuracy Antenna For Radar Satellite

Synthetic Aperture Radar (SAR) satellite is widely used and needed because it is not restrict to air condition or sunlight and it has the penetration power of earth abservation all weather and all the time. The antenna mechanical system is connected the payload to the satellite. The main function of it is to assemble and deploy the antenna, to bear the shocking and vibration during launch and transport, and to ensure the antenna deploying accuracy during orbit. Therefore, the antenna mechanical system plays an important role to the payload performance.With the increasing requirement from the satellite custmor, most payloads need to be more mass, bigger dimension, more complex configuration and higher accuracy. The high stiffness, low response and small deformation during orbit of the antenna mechanism need to be studied in order to achieve the performance requirement. This technique is a vital topic and urgent to be settled in the study on space mechanisms.In this paper, the design for key component of antenna system mechanism are introduced, the structure and mechanism dynamics and thermal deformation during orbit are analyzed according to the weighty payload and high accuracy requirement of a radar satellite. The optimized desigh are performed based on this simulation results which been verified by the mode test results. The mode and vibration test on antenna mechanism are performed which verified the design and optimized method.The factors on antenna stiffness and response are found out based on structure dynamic calculation. The design parameter of mechanism configuration, holddown positions distribution, the distance between antenna and satellite are optimized. Based on this work, the stiffness increasing and response decreasing for antenna system mechanism can be achieved.The model for thermal deformation is built based on orbit environment. The sensitive sourse are focused according to comparision on material, dimension, configation, temperature and connection. The design parameter and adjusted and related measures are carried out so that the thermal deformation can be decreased and the antenna accuracy during orbit can be increased.Based on the work above, the reasonable and optimized design method is given which can meet the requirement of frequency in stowing configration and thermal deformation in deployment configuration. The key technology on large payload and high accuracy of antenna mechanism system are settled which give the foundation on the related product application.