In this work, an estimation of the reverberation time for Ultra-Wideband indoor communication is presented ranging from 2 to 10 GHz. Channel sounding measurements were performed in an indoor environment with a network analyzer and virtual arrays. The concept of a reverberation time is known from the theory of Room Electromagnetics, and can be calculated from the decay rate of the measured power delay profiles. It was found that this reverberation time depends on the used window function in order to shape the frequency-response measurements, and that it decreases with increasing frequency due to path loss.