Compensation method for distorted planar array antennas based on structural–electromagnetic coupling and fast Fourier transform
Complex operating environment could introduce serious degradation to the electromagnetic performance of active phased array antenna in both the main lobe and sidelobe areas. The effective compensation techniques become the key for antenna to perform in reliable service condition. Therefore, a method combined coupled structural-electromagnetic model with two-dimensional fast Fourier transform for compensation is presented. A compensation calculation model of the excitation current for planar array is established accordingly, quantitatively expressing the relationship between the excitation current compensation and the structure error. The adjustment quantities of excitation amplitude and phase can be quickly obtained and implemented to recover a high-quality pattern from a distorted antenna in both the main lobe and sidelobe areas. Lastly, the simulation of the space-based array antenna is illustrated to compensate its property under the impact of space environment and heat power from its electric devices. Furthermore, an experiment platform of an X-band active phased array antenna with 32 × 24 elements is built and tested for the electromagnetic performance compensation. The simulation and experimental results show that the proposed method can guarantee the performance of the service antenna quickly and effectively in the whole observation area.