电磁场近场测试技术研究

发布时间：2018-05-05 15:04

本文选题：天线 + 散射　；参考：《北京理工大学》2014年硕士论文

【摘要】：近场测试技术在电磁场测试技术中起着举足轻重的作用，尤其是在电磁频段利用不断向高端发展、电磁环境日益恶劣、测试精度要求不断提高的现在。近场测试技术有测试准确、空间利用率高、测试环境纯净和保密性强等特点。本文以实际工程项目需求为目标，重点开展了电磁场近场测试的三个方面的技术实现和探索研究，包括：天线近场测试、散射近场测试和近场吸波材料反射率测试技术。天线近场测试技术中首先介绍天线近场测试理论，包括波谱理论、近远场变换和口径反演；并在理论的基础上介绍搭建的天线频域近场测试系统；重点介绍测试系统中采样架控制和矢网控制软件；最后以S波段标准喇叭做测试对比。散射近场测试技术中首先介绍了散射频域近场测试理论，与天线近场测试理论的异同；介绍小双站角测试方案，测量金属球的RCS；重点介绍散射频域近场测试系统中散射数据预处理和图形显示部分的编写；最后给出实际测试结果并与理论结果对比。最后重点讨论了吸波材料反射率的近场测试方法。首先介绍了国军标中吸波材料特性远场测试方法；接着利用电磁仿真工具CST建立了吸波材料反射率的仿真模型，首先用平面波照射吸波材料，然后分别用波导、TEM天线和龙勃透镜天线做探头直接对准吸波材料，，并分析了与理论值的差异；在此基础上利用一种便携式的测量仪，对吸波材料反射率进行了近场实际测试，分别用波导和龙勃透镜天线做探头连接矢量网络分析仪（以下简称矢网，PNA），对特性已知的吸波材料进行现场测量，并分析了测试结果与理论值的差异，得出了结论和对后续工作的建议。
[Abstract]:Near-field testing technology plays an important role in electromagnetic field testing technology, especially in the electromagnetic frequency band use to the high-end development, electromagnetic environment is increasingly bad, testing accuracy requirements are constantly improving. The near-field test technology has the characteristics of accurate test, high space utilization, pure test environment and strong confidentiality. Aiming at the requirements of practical engineering projects, this paper focuses on the implementation and exploration of three aspects of electromagnetic field near field measurement, including antenna near field measurement, scattering near field measurement and near field reflectivity measurement of absorbing materials. In antenna near-field testing technology, the antenna near-field testing theory, including spectrum theory, near-far-field transformation and aperture inversion, is introduced, and the antenna near-field measurement system in frequency domain is introduced based on the theory. The software of sampling frame control and vector network control in the test system is introduced emphatically, and finally, the S-band standard horn is used as the test comparison. In the technique of scattering near field measurement, the theory of scattering near field measurement in frequency domain is introduced firstly, and the similarities and differences between the theory of scattering near field measurement and the near field measurement theory of antenna are introduced, and the small bistatic angle measurement scheme is introduced. The RCSs of metallic spheres are measured, and the preprocessing of scattering data and the compilation of graphics display in the scattering frequency domain near field testing system are introduced. Finally, the actual test results are given and compared with the theoretical results. Finally, the near field measurement method of reflectivity of absorbing materials is discussed. This paper first introduces the far-field measurement method of the characteristics of absorbing materials in the national military standard, then establishes the simulation model of the reflectivity of absorbing materials by using the electromagnetic simulation tool CST, and at first illuminates the absorbing materials with plane waves. Then the waveguides TEM antenna and the Len lens antenna are used as the probes to directly align the absorbing materials, and the difference with the theoretical values is analyzed. On the basis of this, a portable measuring instrument is used to measure the reflectivity of the absorbing materials in the near field. The waveguide and the Lens antenna are used as the probe to connect the vector network analyzer (hereinafter referred to as the vector net PNAN). The field measurement of the absorbing materials with known characteristics is carried out, and the difference between the measured results and the theoretical values is analyzed. Conclusions are drawn and recommendations for follow-up work are made.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM937

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