Stirrer efficiency in FOA reverberation chambers. Evaluation of correlation coefficients and chi-squared tests

In reverberation chambers stirrers are used to change the boundary conditions. The objective is that each location of the stirrer shall create an independent field distribution. This can be evaluated by calculating the correlation coefficients from measured data. To investigate stirrer efficiencies measurements have been performed in our two reverberation chambers. Investigations have been performed using one and two mode-stirrers. Also in focus has been to quantify the criterion that the power received by a linear antenna is supposed to follow a χ²-distribution. The results show that it is necessary to evaluate chamber properties regarding both stirrer correlation and statistical distribution