【作者】 程明军；

【导师】 吴雄英； 王善元；

【作者基本信息】 东华大学 ， 纺织材料与纺织品设计， 2004， 硕士

【摘要】 随着抗电磁辐射织物产生和发展，如何评价其屏蔽效能有着重要的现实意义。本课题在测试抗电磁辐射织物的基本性能基础上，利用法兰同轴方法测试抗电磁辐射织物对平面波的屏蔽效能；利用屏蔽室方法测试抗电磁辐射织物分别对电场源、磁场源的屏蔽效能；通过分析抗电磁辐射织物的屏蔽效能去分析两种测试方法的可靠性，为如何评价抗电磁辐射织物的屏蔽效能提供了基础。主要研究内容如下： (1)本篇论文首先对测试屏蔽材料屏蔽效能的几种主要的测试方法进行回顾和分析，并对目前抗电磁辐射织物主要评价方法——同轴测试方法其优缺点进行简要的分析和总结，并提出一种新的测试方法——屏蔽室方法。 (2)分析抗电磁辐射织物的屏蔽原理，并对法兰同轴测试方法和屏蔽室测试方法的测试原理分别进行分析。 (3)在平面波源下，用法兰同轴测试抗电磁辐射织物的屏蔽效能，并进行重复测试，得到不同次数和不同频率下的屏蔽效能值，在30～1500MHz频率范围内，改变测量次数对屏蔽效能无影响，得出法兰同轴测试方法重复性较好；随着表面比电阻和相对电导率变小屏蔽效能变大，测试结果与基本原理一致。 (4)利用屏蔽室方法分别测试6个试样的对电场源和磁场源屏蔽效能： 对于电场源： 在屏蔽室窗口取600mm×600mm时，测试6个试样的屏蔽效能值，得到在25～300MHz范围，所有试样测试结果稳定性很差，镀金属的织物屏蔽效能值稳定性比加入不锈钢纤维的织物屏蔽效能稳定性好些，在300～3000MHz范围内，6个样品测试结果稳定性较好； 对加入不锈钢纤维的4种织物，变化试样与电磁波入射方向的角度测试试样屏蔽效能，对每个点的屏蔽效能有影响； 对不锈钢织物试样在1000～3000MHz范围，改变发射天线和接收天线的距离，得到发射天线和接收天线的距离在1～3m范围，对每个点值有影响；摘要 对于镀镍织物和不锈钢纤维织物试样，改变试样尺寸测试，得出尺寸对镀镍织物对每个点值有影响; 对于磁场源: 6个试样在30MHz以下，屏蔽效能值为O; (5)对法兰同轴测试方法与屏蔽室方法进行对比得出:法兰同轴方法在30~150OMHz内对平面波测量结果较好，但是法兰同轴只可以测试平面波的屏蔽效能;屏蔽室方法可以测试一般电磁环境下，材料对电场源和磁场源的屏蔽效能，在25一300MHz测试结果稳定性很差，在300~300oMHz测试结果稳定性较好。 (6)讨论抗电磁辐射织物屏蔽效能的测试方法:首先，依据织物的屏蔽频率范围，确定使用何种方法合理;然后根据辐射源的特性，再确认何种测试方法更为合理;最后合理的确定测试样品的尺寸大小。 此外，论文对未来改进的屏蔽室测试方法和发展的趋势作了简单的探讨。更多还原

【Abstract】 As the electromagnetic shielding fabrics has developed and come into being, it is very important to evaluate shielding effectiveness of them.This paper investigated shielding effectiveness (SE) of electromagnetic shielding fabrics under plane wave by coaxial planar and under electric field source or magnetic field source by electromagnetic shielding enclosure. Analyzing shielding effectiveness of the electromagnetic shielding fabrics can get the reliability of above two methods. These laid a foundation on how to evaluate shielding effectiveness of fabrics. The followings are the main research work in this paper.(1) Firstly, this paper reviewed and analyzed main test methods for shielding effectiveness of electromagnetic shielding materials and summed up the virtues and disadvantages of coaxial planar-main test method for determining shielding effectiveness of electromagnetic shielding fabrics . Put forward a new method ofelectromagnetic shielding enclosure.(2) Having analyzed the shielding principle of electromagnetic shieldingfabrics and the principles of above two test methods.(3) Under plane wave, some value of shielding effectiveness (SE) of electromagnetic shielding fabrics can be got under different frequency and different testing time by coaxial planar fabrics repeatedly .The results of above SE value showed that the frequency doesn’t affect the test results. So the coaxial planar has good repeatability. The test results showed increasing while surface resistivity decreasing and are consistent with the shielding principle.(4) The test method of electromagnetic shielding enclosure:For electric field source, while the dimension of window of electromagnetic shielding enclosure is 600mm X 600mm,by testing shielding effectiveness 6 samples, the results showed that all samples have not good repeatability from25MHz to 300MHz and good repeatability from 300 MHz to 3000 MHz.For four samples with stainless steel, (by changing angle of sample with electromagnetic wave), the results showed the angle affects the test effect evidently.For stainless steel fabric, from 1000 MHz to 3000 MHz, by changing the distance between emission antenna and receiving antenna from 1m to 3m, the results showed the distance has affect the test effect evidently.For coated nickel fabric and stainless steel fabric, the results showed the size of sample do affect the test effect evidently;For magnetic field source, all tested samples have no shielding effectiveness.(5) Some effects can be got by comparing coaxial with electromagnetic shielding enclosure. From 30MHz to 1500MHz,the test method of coaxial is good for plane wave and not fit for others. But the electromagnetic shielding enclosure can make up it. It has not good stability from 25MHz to 300MHz and good stability from 300MHz to 3000MHz.(6) This paper discussed the test method of electromagnetic shielding fabrics: first, according to the frequency of fabric shielding, determine reasonable test methods; then, according to the characteristics of radiation, determine reasonable test methods again; finally, determine reasonable the size of sample.Further, this paper discussed improving and developing on the electromagnetic shielding enclosure in the future work.更多还原