Phase retrieval in EM inverse scattering from phaseless data

In this paper phase retrieval in electromagnetic inverse scattering is studied. Both the amplitude and phase of the scattered field are reconstructed from the amplitude of the total field by minimizing a functional that is the norm of the discrepancy between the measured amplitude and the calculated one. The incident wave is used as prior information in the procedure. The effect of degree of freedom of the scattered field and noise on the phase retrieval is analyzed, and the condition of avoiding local minimum is discussed. Experiment results are presented for the first time to show the feasibility of phase retrieval in electromagnetic inverse scattering from phaseless data. The experiment results also show the validity and stability of the method. Both the numerical simulation and the experiment results show that the method is very tolerant to noises. The phase retrieval method proposed will be of practical use for its low computation cost. The result founds a basis for the inverse scattering with phaseless data.