A new technique for optimizing mode-stirred chamber efficiency

Mode-stirred chambers are widely employed throughout industry for performing electromagnetic susceptibility tests on a wide variety of electronic circuits and systems. The interior of this class of shielded electromagnetic chamber possesses a mechanically rotated metallic stirrer which is employed to perturb the internal field patterns. As the stirrer is rotated, this causes variation in the input VSWR of the chamber. This paper presents an electronic technique which compensates for the VSWR fluctuations inherent in this class of shielded chamber, and as a result, produces significantly improved chamber performance.