电磁屏蔽材料的研究进展

阐述了研究电磁屏蔽材料的重要性。综述了表层导电型、填充复合型、本征型导电高分子、导电织物、透明导电薄膜等电磁屏蔽材料的性能及特点,简要阐述了电磁屏蔽材料的发展趋势。     

填充复合型聚合物基电磁屏蔽材料研究进展

综述了近年来填充复合型聚合物基电磁屏蔽材料的国内外最新研究进展，按照填料结构形态（纳微粒子颗粒型填料、高长径比结构填料、片层结构填料、三维网状框架结构填料），对相关复合材料电磁屏蔽性能数据进行统计和对比。围绕构筑高效导电网络的目标，从导电填料选择与处理、基体结构设计与制备方法等角度对聚合物基电磁屏蔽材料进行详细分析与总结，阐明了聚合物基电磁屏蔽材料研究现状及关键问题，阐述了聚合物基电磁屏蔽材料的研究方向和未来发展趋势。     

Ag/Ni/玻璃微珠填充硅橡胶性能

采用自制的导电填料Ag/Ni/玻璃微珠制备了导电硅橡胶,对其形貌进行了表征,对其导电性能、电磁屏蔽效能、力学性能进行了研究。结果表明,Ni的存在使Ag/Ni/玻璃微珠填充硅橡胶在低频的屏蔽效能有所增强,填充体积分数为56%时,导电硅橡胶导电性良好,10 kHz~6 GHz屏蔽效能达70.6~98.8 dB,力学性能良好。     

镀金属碳毡在电磁屏蔽材料中的应用

将三维网络结构的碳毡引入电磁屏蔽材料的应用，对其特有的电磁性能及网络结构作了分析，并进行了复合材料屏蔽效果计算和修正。研究表明：利用碳毡的孔洞结构和尺寸，辅之以金属镀层，能在较宽的频率内对电磁波有良好的屏蔽效率，且不需要很大的填充量。     

全机电子综合试验电磁屏蔽暗室

本文简要说明了全机电子综合试验电磁屏蔽暗室的必要性、优越性，电磁屏蔽暗室的用途以及电磁屏蔽暗室的技术要求和设计原理。     

电磁兼容设计中金属屏蔽镀（涂）层的选用

叙述了在电磁兼容设计中，在选用金属镀（涂）层作电磁屏蔽层时应考虑的因素。强调了屏蔽材料防气候环境条件腐蚀以确保电磁屏蔽性能长期可靠的重要性。分别介绍了针对各种材料制作的蜂窝屏蔽通风板、机壳、屏蔽网、垫片等电子仪器零部件选用的屏蔽镀（涂）层。     

某直升机的电磁屏蔽设计

详细讨论了国家重点工程直升机的电磁屏蔽原理,并对屏蔽效能进行了理论计算,使其设计的屏蔽效能完全达到电磁兼容性标准,不但使机内辐射干扰源对外界电磁环境的干扰有效抑制,又不使外界干扰影响机内设备的正常工作。     

化学镀电磁屏蔽层工艺

化学镀电磁屏蔽层工艺电磁干扰可使电子设备或分系统出现故障或完全失效，电磁屏蔽即为一种可靠、有效的防电磁干扰和防电子信息泄露发射的技术。我所通过对多种化学镀配方及工艺的研究与选择试验，完成了化学镀电磁屏蔽层工艺研究，此工艺成果填补了国内用化学镀方法镀覆...     

民航VHF设备电磁屏蔽技术探讨

本文结合实际工作经验对民航VHF设备电磁屏蔽技术进行了探讨研究，总结VHF设备电磁屏蔽应注意的问题，以供同行参考。     

层状Ti3C2Tx/水性聚氨酯复合双层薄膜的制备及电磁屏蔽性能

采用交替真空抽滤制备Ti_3C_2T_x MXene/WPU复合双层薄膜,用扫描电子显微镜(SEM)和透射电子显微镜(TEM)表征了微观形貌,X射线衍射仪(XRD)测试了晶体结构,通过矢量网络分析仪测试了电磁屏蔽性能。结果表明,可以通过超声离心制备出少层Ti_3C_2T_x;复合双层薄膜具有高韧性、高导电性以及优异的电磁屏蔽性能,表面电阻为3.57Ω;电磁屏蔽性能结果表明,MWPU_(3:1)的复合薄膜屏蔽性能为37.9 dB。在X波段与K波段,MWPU_(3:1)复合薄膜性能较为优异,且复合薄膜是吸收型电磁屏蔽材料。     

电磁屏蔽抗干扰技术研究

从干扰源性质出发,将屏蔽分为电场屏蔽、磁场屏蔽和电磁场屏蔽,并对它们进行了分析研究。针对其特性提出其适用范围及注意事项,从而增强了抗干扰的效果。     

Electromagnetic characteristics of carbon nanotube film materials

Carbon nanotube(CNT) possesses remarkable electrical conductivity, which shows great potential for the application as electromagnetic shielding material.This paper aims to characterize the electromagnetic parameters of a high CNT loading film by using waveguide method.The effects of layer number of CNT laminate, CNT alignment and resin impregnation on the electromagnetic characteristics were analyzed.It is shown that CNT film exhibits anisotropic electromagnetic characteristic.Pristine CNT film shows higher real part of complex permittivity, conductivity and shielding effectiveness when the polarized direction of incident wave is perpendicular to the winding direction of CNT film.For the CNT film laminates, complex permittivity increases with increasing layer number, and correspondingly, shielding effectiveness decreases.The five-layer CNT film shows extraordinary shielding performance with shielding effectiveness ranging from 67 d B to78 d B in X-band.Stretching process induces the alignment of CNTs.When aligned direction of CNTs is parallel to the electric field, CNT film shows negative permittivity and higher conductivity.Moreover, resin impregnation into CNT film leads to the decrease of conductivity and shielding effectiveness.This research will contribute to the structural design for the application of CNT film as electromagnetic shielding materials.     

Preparation of CF/Ni-Fe/CNT/silicone layered rubber for aircraft sealing and electromagnetic interference shielding applications

To meet the needs of preventing information leakage in space engineering and military industry, an efficient method was introduced to obtain layered electromagnetic shielding sealing rubber. The carbon fiber, Ni-Fe coating, and Carbon NanoTube (CNT) were combined by chemical plating and in-situ polymerization to obtain a lightweight (0.14 g/cm²) and thin (1 mm thick) Carbon fiber Fabric (CF)/Ni-Fe/CNT/silicone layered electromagnetic shielding composites. The layered material obtained by adjusting the electroless plating time exhibited a high Shielding Efficiency (SE) of 60.2–85.5 dB in the range of 0–4800 MHz, which can be used for aviation electromagnetic shielding. Carbon fibers and carbon nanotubes mainly attenuated electromagnetic waves through absorption loss, while the nickel-iron alloy coating through reflection loss interacted with the magnetic vector of incident ElectroMagnetic (EM) radiation and magnetic dipoles, therefore, the EM Interference (EMI) shielding composite attenuated EM waves with the “absorption-reflection-absorption” cooperative interaction. Moreover, the flexible fabric substrate adhered with silicone rubber possessed a breaking elongation of 52.3%, which can be utilized as a good sealing material. Simultaneously, the outstanding exothermicity (67.2 °C under the applied voltage of 5 V) makes it possible to be applied in electric heating area. The electromagnetic shielding composites prepared in this paper have good potential in the fields of precision electronic equipment and aviation systems.     

机体屏蔽特性测量

飞机经常在恶劣的电磁环境中飞行,为使机内的设备不受损害,除了保证机载设备具有足够的抗干扰能力外,还应提高蒙皮的屏蔽效能。本文在分析机体屏蔽特性的基础上,着重讨论了飞机屏蔽效能的测试方法,并介绍了提高机身屏蔽效能的设计措施。     

一种可控透波材料电磁性能分析

采用多次化学切换手段考察了一种可控透波材料在不同次数切换前后的透波性能、屏蔽性能、切换时间、表面形貌。结果表明:切换次数10次以内,6~18 GHz材料透波状态透波率随切换次数变化较小,透波态透波率均大于90%,但材料屏蔽状态屏蔽性能增强,屏蔽态反射率均大于44%,透波/屏蔽切换时间变长,屏蔽态到透波态切换时间均在10 s内,透波态到屏蔽态切换时间均在30 s内,表面有氯化铵生成。     

基于FEM的惯导系统电磁屏蔽效能仿真分析

机箱电磁屏蔽效能的优劣影响惯导系统的电磁兼容性能,而孔缝是造成电磁泄露的重要原因。本文运用FEM分析计算软件Ansoft HFSS,分析了缝隙的形状和不同组合对机箱屏蔽效能和谐振频率的影响,提出了改进措施提高屏蔽效能。并对惯导系统电子设备机箱的设计进行了比较,为选择屏蔽效能较好的设计提供了依据。