混响室条件下的腔体屏蔽效能测试方法改进

Improved Test Method for Shielding Effectiveness of Enclosures in Reverberation Chamber

介绍了频率搅拌混响室法腔体屏蔽效能的测试原理与方法,在此基础上,对某开缝腔体的屏蔽效能进行了实测。针对测试中暴露出的单一频率搅拌测试精度不高这一技术难题,从提升样本容量角度出发,采用一种基于机械搅拌与频率搅拌相结合的复合搅拌方式,提升了搅拌带宽内的独立样本数量,降低了测试结果的不确定度。从数据处理方法入手,提出一种基于数字低通滤波获取混响室场量均值曲线的方法,在有效保留峰值信息的同时,能够获得较理想平滑的场量均值曲线,提升了数据处理的精确度。相比两种改进方法,前者需要与机械搅拌配合使用,适用较大腔体屏蔽效能测试;后者不必过多关心样本容量大小,且无需增加额外辅助测试设备,更具应用价值。

The principle of testing the shielding effectiveness （SE） of enclosures in reverberation cham- ber （RC） using frequency-stirred method is introduced briefly. Based on this, the shielding effectiveness of a slotted enclosure is measured. As to the low metering accuracy exposed in test, a combined stirring test technology is proposed, which can significantly increase the sample size in stirring bandwidth, thus reducing the uncertainty of test result. A new method based on digital low-pass filtering is presented to get the mean curves of electric field. The proposed method can effectively retain the peak information and ob- tain the desired smooth of electric field, so it enhances the accuracy of data processing. Compared with the two method, the combined stirring test method needs to combine mechanical stirring with frequency stirring, which is more suitable for large cavity test. The digital low-pass filtering is careless of the sample size and does not need additional test equipment.