Dimensional tolerance optimization of SAR antennas with uncertainty quantification and reliability analysis based on structural-electromagnetic coupling model

The dimensional tolerances greatly impact the structural-electromagnetic performance of spaceborne synthetic aperture radar (SAR) antenna. However, few works have conducted the tolerance allocation of the extendible support structure to guarantee system reliability. To bridge the above gap, an integrated optimization methodology is proposed to design the dimensional tolerances with the structural-electromagnetic coupling model in this study. First, the absolute nodal coordinate formulation is developed to predict the structural deformation triggered by the dimensional deviations. Then, the coupling relationship between the displacement field and the electromagnetic field is elucidated for the SAR system. Subsequently, taking advantage of the surrogate model and the parallel update criterion, the interval uncertainty quantification stemming from dimensional tolerances is executed to quickly identify the worst-case scenarios of structural response. Moreover, a multi-point selection strategy is incorporated into the adaptive Bayesian probabilistic integration with active learning, which significantly improves the computational efficiency of electromagnetic reliability. Based on the above tolerance analysis, the inverse optimization design of the dimensional tolerance is realized by the particle swarm algorithm. Finally, the effectiveness and superiority of the proposed methods are validated in the case study. Our innovative framework and analytical methodology not only furnish a comprehensive structural-electromagnetic coupling model but also transition the design paradigm from experiential to robust tolerance allocation.