Flexibility in Over-the-Air Testing of Receiver Sensitivity With Reverberation Chambers

The next generation of wireless device utilises higher frequencies and a large array of form factors. With miniaturisation of devices and the growth of internet-of-things applications having no connectors for testing, the use of conducted tests is no longer an option and verification of this equipment requires over-the-air measurements. Additionally, some important metrics such as receiver sensitivity requires an actual communication link. Reverberation chambers loaded with lossy absorbers provide an efficient environment to measure such averaged quantities with flexibility in a test volume as well as device size, shape, and placement. Here, the authors present an overview of OTA measurements in reverberation chambers compared to anechoic measurements. The authors show the consistency and flexibility of reverberation chambers through measurements of a wireless device in three different reverberation chamber setups and compare to an anechoic chamber measurement. By using a proper chamber setup, and by showing a coherence bandwidth (CBW) as a universal metric for comparing chamber loading between setups, excellent chamber-to-chamber consistency is shown, without precise placement of the device in each chamber. The authors show empirical evidence for the choice of threshold in determining the CBW.