Diffuse field cross-correlations: scattering theory and electromagnetic experiments

Matthieu Davy (1) , Philippe Besnier (1) , Philipp del Hougne (1, 2) , Julien de Rosny (3) , Elodie Richalot (4) , François Sarrazin (4) , Dmitry V Savin (5) , Fabrice Mortessagne (2) , Ulrich Kuhl (2) , Olivier Legrand (2)

1 IETR - Institut d'Électronique et des Technologies du numéRique
2 INPHYNI - Institut de Physique de Nice
3 IL - Institut Langevin - Ondes et Images (UMR7587)
4 ESYCOM - Electronique, Systèmes de communication et Microsystèmes
5 Brunel University London [Uxbridge]

The passive estimation of impulse responses from ambient noise correlations arouses increasing interest in seismology, acoustics, optics and electromagnetism. Assuming the equipartition of the noise field, the cross-correlation function measured with non-invasive receiving probes converges towards the difference of the causal and anti-causal Green's functions. Here, we consider the case when the receiving field probes are antennas which are well coupled to a complex medium-a scenario of practical relevance in electromagnetism. We propose a general approach based on the scattering matrix formalism to explore the convergence of the cross-correlation function. The analytically derived theoretical results for chaotic systems are confirmed in microwave measurements within a mode-stirred reverberation chamber. This study provides new fundamental insights into the Green's function retrieval technique and paves the way for a new technique to characterize electromagnetic antennas.

Domaines: Physique [physics]

Matthieu Davy, Philippe Besnier, Philipp del Hougne, Julien de Rosny, Elodie Richalot, et al.. Diffuse field cross-correlations: scattering theory and electromagnetic experiments. Physical Review E , 2021, 104 (4), ⟨10.1103/PhysRevE.104.044204⟩. ⟨hal-03409103⟩