A Full-Wave Inversion Method for Perfectly Electric Conductors in an Iterative Framework

An efficient, accurate, and robust inversion algorithm is proposed in this work to reconstruct perfect electric conductor (PEC) scatterers, which considers the complex multiple scattering effects and employs a full-wave approach to address the inverse scattering problems (ISPs) of metallic structures. To perform the inverse scattering without prior knowledge of the scatterers, a diagonal matrix is introduced to represent the PECs, extending the mapping between the scattered field and the surface current across the entire computational domain. Furthermore, to improve the efficiency of the inversion, matrix transformations are employed to keep the nondiagonal elements zero, thus reducing the computational complexity. Additionally, to address the ill-posedness caused by the insufficient data and the noise interference in the ISPs, the Tikhonov regularization method is introduced, where the regularization parameter is adaptively determined by the L-curve method. To demonstrate the effectiveness of the proposed method, several typical 2-D experiments were considered, and the results show that the method can accurately and efficiently reconstruct the complex PEC scatterers, even in the presence of strong noise.