Empirical Study of Angular–Temporal Spectra in a Reverberation Chamber

The previous experimental studies on angular spectra of reverberation chambers (RCs) were conducted by either rotating a directive horn antenna (which suffers from low resolution) or using conventional beamforming (whose beam varies with frequency), resulting in inaccurate characterizations of angular statistics of the broadband channel in the RC. To avoid this problem, we resort to a frequency-invariant beamformer for the evaluation of the angular-temporal spectra of the RC. Contrary to the previous studies, it is found that modest loading does not increase the statistical anisotropy in the delay domain (after the ramp-up stage of the power delay profile) as compared with the unloaded case, implying that modest loading does not alter RC's angular statistics for over-the-air testing.