Numerical Modeling of the Reverberation Chamber Method for the Measurement of Material Absorbing Cross Section

Reverberation chamber (RC) test facility allows to determine the absorbing cross section (ACS) of lossy materials under a random field excitation. Measurements are based on the quality factor variation produced by the sample under test presence with respect to the empty chamber condition. Simulations are based on the representation of the RC electromagnetic field by means of a random plane wave superposition. A finite-difference time-domain (FDTD) code is used to compute the material absorbed power and to recover a numerical ACS. The method sensibility is stressed by application to small size samples. Comparison between numerical and experimental data reveals a satisfactory agreement. The simulation technique can be applied to study the absorbing properties of absorbers with arbitrary geometry during the early design stage.