吸波材料理想电磁参数区域的数值模拟及实验改性研究

发布时间：2018-08-27 09:50

【摘要】：在信息技术迅速发展的时代,大量电子设备被广泛应用,与此同时会产生大量电磁波辐射,从而严重影响人们的正常生活,因此,对吸波材料的研究具有非常重要的实际意义。运用吸波材料不仅能够减少电磁波对人类的伤害,而且在武器装备方面可以弥补隐身方面的不足,增强军队的作战能力。由于影响吸波材料吸波性能的因素较多,研究过程中需要克服很多困难,仅仅依靠传统的方法和实验已经无法满足日益增长的科研需要。因此,应用计算机辅助研究可以减少实验的盲目性、节约成本、提高研究的效率。本文引入传输线理论方法对电损耗型吸波剂和磁损耗型吸波剂的理想电磁参数区域进行了模拟研究,并通过制备PANI/Fe_3O_4纳米复合材料对模拟结果进行验证。以电损耗型吸波剂为研究基础,根据传输线理论模拟获得给定条件下的复介电常数的理想电磁参数区域,预测吸波剂在不同频段下的吸波性能并找到吸波剂改性的方向。并考察厚度(d)、频率(f)、反射率(R)等因素对理想电磁参数区域的影响。用硬模板法制备得到了平均粒径约为800 nm的PANI中空微球,通过矢量网络分析仪测试其电磁参数。将测试的结果与模拟结果相结合进行分析,找到提高电损耗型PANI电磁参数的方向进行改性,以提高其吸波性能。同样的道理得到了磁损耗型吸波剂复磁导率的理想电磁参数区域,并分析厚度(d)、频率(f)、反射率(R)等因素对理想电磁参数区域的影响。研究结果表明,纯的PANI具有较高的电损耗而磁损耗较低,电磁匹配程度较差,吸波性能不理想。结合模拟结果和实验数据得到改善PANI电磁匹配特性的方向是提高其磁损耗的能力,在中空结构PANI表面负载Fe_3O_4后,复合材料的介电损耗降低,磁损耗增加,使得介电损耗角正切(tanδε)和磁损耗角正切(tanδμ)相接近,电磁匹配特性得到改善,上述实验结论与模拟结果相吻合。
[Abstract]:In the era of rapid development of information technology, a large number of electronic devices are widely used, at the same time will produce a large number of electromagnetic wave radiation, which seriously affect the normal life of people, therefore, the study of wave absorbing materials has very important practical significance. The use of absorbing materials can not only reduce the harm of electromagnetic waves to human beings, but also make up for the invisibility in weapon and equipment, and enhance the combat capability of the army. Because there are many factors that affect the absorbing properties of microwave absorbing materials, many difficulties need to be overcome in the research process, and the traditional methods and experiments alone can not meet the increasing scientific research needs. Therefore, the application of computer aided research can reduce the blindness of experiments, save cost and improve the efficiency of research. In this paper, the transmission line theory is introduced to simulate the ideal electromagnetic parameters of the electric loss absorbers and magnetic loss absorbers, and the simulation results are verified by the preparation of PANI/Fe_3O_4 nanocomposites. Based on the theory of transmission line, the ideal electromagnetic parameters of complex dielectric constant under given conditions are obtained by using the theory of transmission line. The absorbing performance of the absorber in different frequency bands is predicted and the direction of modification of the absorber is found. The influence of thickness (d), frequency (f), reflectivity (R) and other factors on the region of ideal electromagnetic parameters was investigated. PANI hollow microspheres with an average diameter of about 800 nm were prepared by hard template method and their electromagnetic parameters were measured by vector network analyzer. Based on the analysis of the test results and the simulation results, the direction of improving the electromagnetic parameters of PANI with electric loss is found to improve its absorbing performance. In the same way, the ideal electromagnetic parameter region of complex permeability of magnetic loss absorber is obtained, and the influence of thickness (d), frequency (f), reflectivity (R) on the ideal electromagnetic parameter region is analyzed. The results show that pure PANI has high loss, low magnetic loss, poor electromagnetic matching and poor absorbing performance. Combined with the simulation results and experimental data, the direction of improving the electromagnetic matching characteristics of PANI is to improve its ability of magnetic loss. The dielectric loss and magnetic loss of the composites decrease after the hollow structure PANI surface is loaded with Fe_3O_4, and the magnetic loss increases. The dielectric loss angle tangent (tan 未蔚) and magnetic loss angle tangent (tan 未渭) are close to each other, and the electromagnetic matching characteristics are improved. The experimental results are in agreement with the simulation results.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB34

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