An inverse scattering approach for inspecting dielectric scatterers at microwave frequencies without phase information

Microwave imaging techniques aim at inspecting targets by using interrogating microwaves. In recent years, several numerical inversion methods and prototypes of microwave imaging systems have been developed. In most cases, they consider an illuminating apparatus and one or more probes used to measure the field scattered by the target; usually, the values of the amplitudes and phases of the field samples are needed. In this work, a hybrid approach for phaseless imaging of dielectric targets is proposed. A two-probe measurement strategy with the related phase-retrieval method is adopted in conjunction with an inversion procedure based on an inexact-Newton method to give an efficient and low-cost imaging setup. Preliminary numerical and experimental validations are discussed.