Evaluation of the reverberant environment of carbon-fiber composite airframes

The interior of a metallic aircraft can be modeled as a reverberant chamber to successfully predict the shielding effectiveness of aircraft. However, with the trajectory of aircraft design, planes will soon be constructed not with aluminum skin, which fits well with the reverberation chamber model, but with composite skin. It is not clear that a reverberation chamber constructed from composite materials will in fact reverberate. This study seeks to fill this void by constructing a carbon-fiber composite chamber and evaluating its reverberation characteristics through direct measurement. The results of the study can then be used to establish the validity of the reverberant assumption for carbon-fiber composite airframes. Chamber quality metrics such as the Max-to-Average Ratio (MAR) test and the Coefficient of Variation (CV) test are presented from 3 GHz to 6 GHz along with representative single frequency distributions. Measurement data from the chamber is in good agreement with theoretical values.