A new optimization algorithm—Improved Mayfly Optimization Algorithm (IMOA)—is proposed in this paper to fulfill the low sidelobe level (SLL) design requirements of the spaceborne array antenna. MOA is a new heuristic algorithm inspired by the flying behavior and mating process of mayflies. It has a unique speed updating system with great convergence, strong stability, fast solution speed, and high precision. Based on the MOA, IMOA not only introduces the adaptive inertial weight factor to enhance the search ability, but also uses the Levy flight strategy and the golden sine operator to improve the disadvantage of easily falling into the local optimal solution. Firstly, according to the antenna pattern requirements of high gain and low sidelobe, an optimization problem model is carried out. Then, the IMOA is applied to solve the problem by only controlling the phase under a given secondary amplitude distribution. Simulation results show that IMOA has great advantages in the maximum sidelobe level (MSLL) suppression and convergence speed. Finally, the EM simulations are conducted on the 528-element planar array antenna. The maximum sidelobe level suppression performances in the test are very consistent with the theoretical simulation, which verifies the feasibility and effectiveness of the proposed IMOA.

For the purpose of fulfilling the low sidelobe level (SLL) requirements for spaceborne phased array antenna pattern synthesis, this paper proposes a new improved whale optimization algorithm (IWOA). As a type of new heuristic algorithm inspired by whale hunting behavior, WOA has the advantages of simple structure, few parameters, fast optimization speed, and high precision. In this paper, improvements are made in three aspects of adaptive weight, spiral coefficient optimization, and optimal neighborhood perturbation, and the proposed algorithm is successfully applied to the intelligent calculation of antenna synthesis. In light of the engineering requirements, the mathematical model of the optimization problem is established, and the desired antenna pattern with high gain and low sidelobe is obtained using IWOA under the constraint that the amplitude variation is within 20 dB. Simulation results demonstrate that IWOA is superior in maximum sidelobe level (MSLL) suppression and convergence. Consequently, EM simulations were conducted on a 64-element planar array, with the results consistent with the theoretical simulation, verifying the feasibility and effectiveness of the proposed algorithm.

This letter proposes an improved scheme for low‐sidelobe beam broadening of spaceborne large‐scale phased arrays, addressing the efficiency and performance limitations of typical algorithms in synergistically achieving controllable beamwidth, low sidelobe suppression and high solution robustness. By integrating a dynamic subarray partitioning mechanism into crossover and mutation operations and optimizing the fitness function with a robustness constraint term, the scheme enhances optimization capability. Comparative experiments under varied beam pointing directions confirm the scheme's effectiveness: the SA‐JADE algorithm stably meets beam broadening targets with excellent sidelobe suppression and solution robustness, offering reliable technical support for spaceborne phased array applications.