Reverberation-Chamber Performance of the Oscillating-Wall Stirrer for Estimating Antenna Efficiency

Mode-stirring mechanisms play a critical role in randomizing the fields in a reverberation chamber such that, on average, the chamber provides a uniform field everywhere in the working volume. Recently, a new type of quasi-wall stirring mechanism, the so-called oscillating-wall stirrer was introduced to increase the working volume, without reducing chamber performance. For the first time, we analyze the performance of that stirrer above 1 GHz, for the application of testing antenna efficiency. We investigate this by analyzing the coherence distance of the oscillating-wall stirrer, and the spatial uniformity. We conclude that, for the most stringent threshold, the oscillating-wall stirrer can provide sufficient samples for a single measurement of antenna efficiency above 1 GHz, with uncertainty due to lack of spatial uniformity better than 0.15 dB.