Frequency Stirring: An Alternate Approach to Mechanical Mode-Stirring for theConduct of Electromagnetic Susceptibility Testing

摘要

This study summarizes the results of an experiment designed to determine theeffectiveness of using frequency stirring to provide field homogeneity in a reverberation chamber. Frequency stirring is accomplished by up-converting band limited white Gaussian noise to microwave frequencies and thus exploits both the high mode densities achievable in a narrow bandwidth at microwave frequencies and the pseudo-statistical nature of the reverberation chamber's eigenmodes. The ultimate goal is to replace the mechanical stirring devices currently used in reverberating chambers with an equivalent electronic eigenmode stirrer. In addition, an expression for the net Q of a reverberation chamber is developed which includes the effects of antenna loading; methods for predicting the homogeneity of the resulting fields in the chamber after application of the frequency stir technique are proposed; and a theoretical basis for interpreting fringe power density levels, cross sections, and shielding effectiveness measurements is also given.