Performance of reverberation chambers using the "well-stirred condition method"

Abstract

In this chapter, the well-stirred condition method is presented in the case of a mechanically stirred reverberation chamber. This method is able to determine the frequency fwscwhere the well-stirred condition of an reverberation chamber is achieved. The method focusing on the ability of the reverberation chamber to produce stirred contributions compatible with the well-stirred condition presents the advantage to be independent of the type, location and orientation of the emitting antenna if the antenna is sufficiently matched over the whole bandwidth. The method based on S11 measurements of an antenna is simple to set up (only a VNA is required) and fast (a few minutes). The method relies on a clear definition of the well-stirred condition and uses threshold values related to theory. Finally, the method is usable in the presence of an EUT (even a heavily lossy one) provided that the antenna is located sufficiently far from it. This has the double advantage to give an overview of the reverberation chamber performance in the exact conditions of the subsequent test and also allows the field strength generated in the reverberation chamber for a given injected power to be predicted. The inherent uncertainty of the method outputs combining the overall uncertainty of the reverberation chamber itself and of the PCF process is estimated to be lower than 10%.