Description

Background: To fulfill its missions, the CEA Le Ripault carries out electromagnetic characterization of materials. Various methods are used to perform these measurements. A recent PhD thesis focused on the application of Bayesian methods to microwave mapping. This thesis led to the development of an impedance mapping technique.

Aim of the thesis: The proposed thesis will focus on two areas: firstly, the application of this mapping method to reflectivity measurements carried out on a near-field characterization bench through calculation/measurement comparison studies; and secondly, the generalization of the method to mapping the radio-electrical properties of a coating.

Thesis procedure: After studying the principle of the method and familiarizing themselves with the software that implements it, the candidate will define an approach to compare the method’s performance with characterizations of real coatings. They will implement this approach to demonstrate the capability of the test bench and the method to determine the impedance of a coating, as well as the uncertainty associated with the measurement. In parallel, they will work to extend the Bayesian method to map the dielectric or magnetic properties of a coating.

Skills required

Master or engineer diploma, in at least one of the following domain: image and signal processing, applied physics, applied mathematics, numerical modeling

Bibliography

T. Benoudiba-Campanini, J.-F. Giovannelli, and P. Minvielle, ' SPRITE : A New Sparse Approach for 3D High Resolution RCS Imaging', IEEE Transactions on Computational Imaging, vol. 6, 2020.

X. Faget, A. Litman, E. Dieudonné, S. Enoch, N. Mallejac. Free-Space Characterization of the Permeability of Inhomogeneous Magneto-Dielectric Materials. IEEE Transactions on Microwave Theory and Techniques, 2017, 65 (12), pp.5035 - 5045

C. Scotti, S. Enoch, M. Groisil, N. Mallejac, Characterization of Inhomogeneous FDM Manufactured Materials: Comparison of Free-Space and Mixing Laws, Progress In Electromagnetics Research M, 2025, Vol. 134, 59-67

Keywords

applied mathematics, electromagnetism, inverse problems, signal processing, microwave imaging