Synthesis of conformal array antenna for hypersonic platform SAR using modified particle swarm optimisation

The synthetic aperture radar (SAR) system equipped on the hypersonic platform in the near space presents many advantages compared with the conventional airborne SAR. However, due to the complex aerodynamic configuration and flight characteristics of the hypersonic platform, the radar design is facing some new challenges. Taking into account the new features of the platform, in this study the authors analyse the conformal design requirements of the array antenna, as well as the prominent contradiction between the high resolution and wide swath of SAR. After establishing the model of the conformal array antenna and the space coordinate system of the far-field radiation, a specific process of synthesising the antenna pattern is given. Furthermore, the antenna mask templates of optimising the antenna pattern are generated based on the main performance measures of the SAR system, and the modified meta particle swarm optimisation algorithm is exploited to obtain the optimal excitation phase of each array element in synthesising the ultimate antenna pattern. Finally, simulation results verify the effectiveness of the method, where the performance of the optimised antenna pattern is evaluated numerically.