Dynamic Analysis and Optimization of Deployment Mechanism of Long-baseline Millimeter-wave Antenna

The spaceborne millimeter wave SAR system has a high frequency band, which requires a high beam pointing stability when operating in orbit. The effect of space micro vibration on its beam direction is obvious. Therefore, in order to ensure the normal operation of the system in orbit, a higher support stiffness is required for the antenna deployment mechanism. In this paper, the spaceborne millimeter wave orbit crossing interference antenna was taken as the research object. According to the index requirements, the configuration design and on orbit dynamics analysis of the antenna in the folded and deployed state were carried out, and the weak components were identified. The first order natural frequency of the SAR antenna deployment configuration was taken as the target to optimize the design of each weak component, and the optimized antenna fundamental frequency reached 8.03Hz, meeting the requirements that the index was greater than 7Hz. The mass and retraction envelope of the optimized antenna mechanism were within the constraints of the satellite and the carrier. In addition, the dynamic simulation analysis of the optimized antenna structure was carried out. With the three-axis attitude angle of the satellite as the input condition, the mechanical center relative to the three-axis angle deviation of the orbital intersection interference antenna on both sides was analyzed. The results show that the error and beam stability meet the index requirements and do not affect the imaging quality of SAR antenna.