混响室可以用较小的功率在大的测量空间获得高的场强和大的动态范围,具有用途广泛、节约测量空间、节省经费等优点,利用混响室技术进行电磁兼容性测试已经成为一个新的研究热点.针对目前国内外缺少混响室环境下小尺寸屏蔽体屏蔽效能测试标准的现状,利用虚拟仪器技术设计和开发了一套小尺寸屏蔽体屏蔽效能自动测试系统.实验结果表明:该测试系统不用回避屏蔽体自身谐振频点的测量,能够实时计算和显示屏蔽体的屏蔽效能,且测量结果重复性好,5次测量数值最大偏差约为1 dB,变异系数小于0.032.
Reverberation chamber (RC) can obtain high electric field intensity and broad dynamic range by low power, and RC has other unique advantages, such as wide usage, big working volume, fund-saving, and so on. RC measuring techniques have been received by international research fellows and standard organizations. Regarding to the shortage of standard testing methods for shielding effectiveness (SE) of small enclosure in RC, a new testing system based on the statistic definition and multi-points measurements of SE has been successfully designed and developed. The tests consequences indicate that this new system allows the tests at resonant frequencies,and the results can be counted and showed at real-time. The randomness of the tests result was reduced in wide range, the biggest deviation of the data in five different times is about 1dB, and the coefficient of variability is less than 0.032.
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