Exploring Uniformity of Reverberation Chambers: Insights from Antenna Reflection Coefficient

Reverberation chambers are widely recognized as a time-efficient testing facility for various applications. The spatial uniformity based on the power transfer function is a critical characteristic of the chamber that affects the measurement uncertainty. To gain more insights into the chamber behavior we introduce a complementary metric: the K-gamma factor. This metric, inspired by the well-established K-factor, quantifies the unstirred contributions of the chamber for each antenna individually and is highly sensitive to the chamber configuration and antenna placement. Analyzing this metric can help identify any undesired effect, such as specular reflections, and, ultimately, improve measurement accuracy. To highlight the usefulness of this metric, two different loading configurations of a reverberation chamber at millimeter-wave frequencies are evaluated as examples.