Full-Wave Characterization of Reverberation Chambers for Rodent Bioassays: Methodology and Realistic-Loading Impact Analysis

This study presents a comprehensive full-wave numerical dosimetry approach for large-scale rodent bioassays in Reverberation Chambers (RCs), improving upon prior methods that rely on idealized Plane Wave (PW) superposition. A ‘‘digital twin’’ of the Università Politecnica delle Marche RC was implemented using Transmission-Line Matrix and Finite Element Method solvers to characterize exposure homogeneity across rodent cages at 900 MHz. Unlike PW-superposition models, loaded-RC simulations account for realistic experimental constraints, such as intruding water-supply metal piping, specific antenna designs and placements, and actual mode stirrers. The loaded-RC electromagnetic characteristics were investigated by analyzing the field impedance ratios, yielding discrimination criteria for the probe location and type. Cage-wise instantaneous and ensemble-averaged whole-body specific absorption rate (wbSAR) distributions were evaluated using postured homogeneous rat models. Furthermore, investigations into exposure imbalance mitigation strategies demonstrated significant benefits when spinning cage assemblies. An analysis of mass-dependent exposures revealed a notably weaker correlation between body mass and wbSAR, as well as a much larger wbSAR cage dependence, compared to earlier PW-based predictions, further highlighting the necessity of realistic RC modeling for reliable rodent bioassay exposure design