Effect of antenna aperture, EUT and stirrer step size on measurements in mode-stirred reverberation chambers

Analysis and results are presented that quantify the effect of the nonzero size of the EUT, antenna aperture or stirrer step on the measured vs. the actual physical field inside and performance of a reverberation chamber. The effect of local averaging on the variance function, normalized spectral bandwidth, upward threshold crossing frequency and mean excursion length of the reverberation process is calculated, both for local spatial averaging and local stir averaging. Experimental results are shown that demonstrate the effect of aperture size on the measured coefficient of variation, spectral bandwidth and field anisotropy coefficients