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本文较详细地、系统地论述了国外最近在解决电子设备电磁干扰方面的一些新技术。全文共分五部份,刊登于美国微波杂志82年6、7、8、9、10期上。为了便于读者了解全文的概况,译者先简略地介绍于后: 第一部份:从理论上论述发射体和感受器之间存在的各种干扰以及屏蔽效率(SE)计算的公式及图表。第二部份:论述在机柜、机箱面板上打孔与电磁干扰的关系。由于通风散热和监示设备工作状态的需要,免不了要在机柜面板上开较大面积的孔洞。为了防止电磁场的泄漏,而采用各种形式的金属屏蔽网,利用波导效应制成蜂窝状的屏蔽窗。用最新工艺将导电材料喷涂在塑料机壳和透明的塑料和玻璃上,既能达到良好的屏蔽,同时又满足监示设备工作状态之需要。为了解决缝隙部位所产生的干扰,在缝隙处使用导电屏蔽衬垫。第三部分:为解决缝隙干扰,常将屏蔽体加以密封,通常采用特制的橡胶。对于各种橡胶使用的环境条件以及它们与金属的共容性,这部份作了较详细的叙述。第四部份:提出三种方法来测量屏蔽衬垫。并引用了美国军用标准MIL—STD—285中所规定的测试方法,并提出一种测试屏蔽衬垫的传输阻抗装置的新方法。第五部份:详细地论述了屏蔽衬垫,并进入实质性设计。从衬垫形状到能承受多大压力;衬垫变形量,制造公差;以及与衬垫配合的法兰盘开口槽大小公差;将衬垫放入槽中盖板上用螺钉紧固时所需间距的计算公式。在本文中,讨论各种屏蔽、使用各种材料、计算各种屏蔽效率时,都涉及到工作频率、系统噪声的大小等电性能指标。文中具有较多的测试曲线和数据。工作频率从几千赫到一万兆赫,发射机输出功率从1W到50KW。这样带宽的频率范围和输出电平,可以说包括了大部份通信和雷达系统的工作频段。文中提到的新屏蔽材料,新工艺、测试新技术、屏蔽新结构;目前在国内少有甚至还未开展。这对于从事电子工艺线路、结构、工艺设计的同志来说有较大的启示和值得借鉴的地方。因为本文涉及知识面较广,特别是电路方面,加之本人外文水平较低,工作能力有限,难免有译错之处, 或不能充分表述原作者的意图,敬请读者批评指正,本人表示感谢!
In this paper, in more detail and systematically discusses the foreign foreign countries in the recent resolution of electromagnetic interference in electronic equipment some new technologies. The full text is divided into five parts, published in the United States of America microwave magazine in June 6,7,8,9,10 period. In order to facilitate readers to understand the general situation of the full text, the translator first briefly introduces later: Part I: Theoretically discusses the various interferences between emitters and susceptors, as well as the calculation formula of shield efficiency (SE) and the chart. The second part: Discusses the relationship between the holes in the cabinet and chassis panel and electromagnetic interference. Due to ventilation and cooling equipment and monitoring the work needs of equipment, inevitably have to open a large area in the cabinet panel holes. In order to prevent electromagnetic field leakage, and the use of various forms of metal shielding network, the use of waveguide effect made of honeycomb shielding window. The latest technology will be conductive material sprayed on the plastic case and transparent plastic and glass, both to achieve good shielding, while meeting the working conditions of the monitoring equipment needs. To address the interference created by the crevice, a conductive shield was used at the crevice. The third part: In order to solve the gap interference, often shield to be sealed, usually using a special rubber. Environmental conditions for the use of various rubber and their compatibility with the metal, this part made a more detailed description. Part IV: Proposed three ways to measure the shielding liner. The test method stipulated in MIL-STD-285 is also quoted and a new method of testing the transmission impedance of the shielding gasket is proposed. Part V: Discussed in detail the shielding liner, and into the substantive design. How much pressure can be exerted from the shape of the liner; the amount of deformation of the liner, the manufacturing tolerances; and the size tolerance of the opening of the flange to be fitted with the liner; the required spacing for fastening the liner to the cover with screws The formula. In this paper, discuss various shielding, using a variety of materials, calculation of various shielding efficiency, are related to the operating frequency, the size of the system noise and other electrical performance indicators. The article has more test curves and data. Operating frequency from a few thousand Hz to ten thousand MHz, the transmitter output power from 1W to 50KW. The bandwidth of this frequency range and output level, it can be said that most of the communications and radar systems include the working band. Mentioned in the new shielding materials, new technology, testing new technology, shielding the new structure; at present there is little or even not yet carried out in China. This is engaged in the electronic circuit technology, structure, process design comrades have greater inspiration and is worth learning. Because this article involves a wide range of knowledge, especially the circuit, coupled with my low level of foreign language skills, limited ability to work, it is inevitable that there are mistakes, or can not fully express the original author’s intention, please readers criticism, I am grateful!