This paper presents reference measurements of 2 × 2 UWB antenna arrays consisting of discone antennas with a frequency range from 2 - 6 GHz performed in a reverberation chamber. The measurements are used to evaluate the diversity gain of arrays with different topologies as well as MIMO capacity. Results of comparing the diversity gain results with line of sight (LOS) and non-LOS indoor measurements are also presented. The reverberation measurements at three frequencies in the band were found to follow a Rayleigh distribution, whereas the indoor LOS measurements presented Rician distribution.