# Structural Optimization Design of Spaceborne Microwave Probe Antenna
[18] set the normal acceleration in a specific region as the core objective of topology optimization and constructed an optimization model based on this. The rib layout was reconstructed, and different optimized layouts were obtained according to different excitation conditions. In the area of controlling and optimizing the antenna perturbation moment, more of the literature focuses on reducing the perturbation moment by optimizing the control algorithm or performing moment compensation [19; 20; 21; 22; 23; 24]. The structural optimization design of the reflective surface reinforcement of the antenna scanning drive mechanism is crucial for increasing the dynamic stiffness of the structure and reducing rotational inertia. It also helps to reduce the effect of moment perturbation. However, in many existing designs, the layout and sizing of the reinforcement bars are mostly dependent on the experience of the designer and lack a supporting theoretical basis. This leads to suboptimal layout and sizing in many designs, deviating from the ideal conditions for optimal design. In order to address the challenges associated with the reflective surface structure of the antenna scanning drive mechanism, this paper proposes a design method that integrates both topology optimization and size optimization. This integrated approach is progressive, where topology optimization lays the foundation by providing the initial design direction and defining the optimal material distribution for the structure. Once the topology is established, size optimization comes into play to precisely adjust the dimensions of the reinforcement, ensuring that the structural stiffness requirements are met while simultaneously optimizing the distribution of mass for improved performance. By combining these two complementary optimization techniques, this method achieves a balanced solution that enhances the overall structural efficiency, reduces rotational inertia, and improves dynamic stiffness, ultimately improving the stability and operational performance of the antenna scanning drive mechanism. The topology optimization adopts the volume as the constraint, the objective function is the maximum first-order frequency, and the results show that the layout of the reinforcement bar along the center presents a \"palm\"-shaped arrangement, which can significantly increase the first-order intrinsic frequency. Based on the topological configuration of the reflecting surface reinforcement structure, the size optimization of the reflecting surface is carried out. Here, the design variables are the thickness of the reflecting surface and the cross-section size of the reinforcement. The objective of such size optimization is to reduce the rotational moment of inertia of the structure, and the constraints are the dynamic stiffness and the RMS of the structure's stress value. The structure's dynamic stiffness improves after the size optimization, and the mass of the reinforcement is significantly reduced. Additionally, the planar antenna's rotational moment of inertia is lower, leading to a reduction in the disturbance moment at both uniform and variable speeds. It is important to adjust the dynamic stiffness and the moment of inertia of the system, which helps to minimize the effect of moment perturbation. In this article, the authors explore the optimization design of reinforcement structures in antenna scanning mechanisms for spaceborne microwave sounders. Section 2 describes the scanning drive mechanism, highlighting disturbance moments from motor torque and dynamic imbalance. Section 3 covers topology optimization, aiming to increase structural dynamic stiffness while reducing rotational inertia by optimizing the reinforcement layout. Section 4 discusses size optimization based on topology results, minimizing rotational inertia and improving system stability, ensuring that the structure is both lightweight and efficient.