Experimental Investigation of Electromagnetic Reverberation Characteristics as a Function of UWB Frequencies

The electromagnetic reverberation time characteristics of indoor environments are experimentally investigated from 2 to 10 GHz. At a given frequency, the reverberation time is observed to be approximately constant for bandwidths up to 900 MHz (or larger). Moreover, the reverberation time decreases for increasing frequencies. Based on the theory of electromagnetic fields in cavities, a model to predict a room's quality factor, reverberation time value, and average absorption coefficient is developed for the first time. The validity and robustness of the model is investigated with data obtained for various environments, central frequencies, and bandwidths. As a validation, the model is applied to another room from 2 to 10 GHz and a maximum (resp. average) relative error of 22.30% (resp. 8.80%) was obtained with a rms error of 1.90 ns. Furthermore, good agreement is obtained with results reported in the literature with settings falling into the model range; scenarios for which relative errors smaller than 10% were computed. The results demonstrate that this approach is not only an accurate alternative to the reverberation time measurements and computations in indoor environments from 2 to 10 GHz, but also a viable route to link propagation mechanisms in indoor scenarios with reverberation chambers.