A numerical-optimizing method of metasurface inverse design based on method of moment and particle swarm optimization for the scattering field modulation

In this paper, an efficient numerical-optimizing hybrid method for manipulating the scattering field of electromagnetic metasurfaces was proposed. Firstly, a mathematical model of a metasurface based on surface impedance was established. The surface impedance was calculated using the method of moments in numerical. Secondly, an improved particle swarm optimization algorithm was proposed to optimize the surface impedance so that the real part of the surface impedance is zero. Finally, to realize the optimized surface impedance physically, classical capacitive structures were considered and verified in full-wave simulation. It was demonstrated that the scattering field generated by the physical structure closely matched the desired field, which demonstrated the effectiveness and accuracy of the proposed method. The proposed method provides a systematic and efficient method for metasurfaces design, enabling precise modulation of scattering fields. The method proposed in this paper has a great time advantage compared with the conventional design methods of metasurface.