基于LabVIEW的微波自动化测试研究

发布时间：2018-03-16 11:30

本文选题：复介电常数　切入点：高次模　出处：《电子科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着微波技术日新月异的发展,材料介电特性的研究与测量是现代科技领域中的重要组成部分,也广泛的应用于能源、通讯、生物医疗、电子等等的各个领域,介质复介电常数测试研究显得尤为重要。同时随着计算机技术的不断进步与发展,自动化测量技术越来越多的应用到微波测试领域,在复介电常数测试中更加高效的完成复介电常数的测试显得十分必要。新型材料的不断出现,纳米材料以其独特的特性在微波领域扮演者越来越重要的角色,纳米材料介电特性的研究已经成为当下研究的热点。本文与大多数复介电常数采用的测试方法不同的是,我们应用高次模模式进行复介电常数的测量,不仅有利于观察材料介电特性的高频特性也有利于数据的处理分析。基于实验室现有条件,选取了矩形谐振腔微扰法进行复介电常数测试,同时利用电磁仿真软件HFSS综合选取了0～3GHz频段内的高次模模式,并进行模式分析,最后确定选取测试用的频点模式。接着推导了矩形谐振腔微扰法复介电常数计算公式,并给出了实际测试中需要的测试参量。基于LabVIEW2012完成了复介电常数自动测试软件的编写,使其能够高效的控制AV3620A矢量网络分析仪进行测试。为验证测试系统的正确性与稳定性,测试了聚四氟乙烯、树脂玻璃、尼龙的复介电常数,测试结果显示其稳定性良好精度较高。伴随着纳米材料的涌现,以碳纳米管为代表的等一批新型微波吸波材料的介电特性的精确测量也逐步深入。文中采用碳纳米管与液体石蜡混合这一新颖的方式进行混合物的制备与测量。这种方式改善了混合过程中的均匀性,从而减少了样品制备过程中的误差,增加了数据的准确性,用编写的自动测试系统测试了碳纳米管/石蜡混合物的介电特性,结果显示其具有较好的吸波特性。最后文中给出了一种基于HFSS仿真软件非标准样品复介电常数的数据修正,对于一些非标准样品的复介电常数的测试利用实验测试与仿真相结合的方法进行数据修正,验证了高损耗非标准样品的数据修正值,结果显示其与标准值相差较小,在无法进行标准测量的情况下可以作为其介电特性的参考。
[Abstract]:With the rapid development of microwave technology, the study and measurement of dielectric properties of materials is an important part in the field of modern science and technology. It is also widely used in energy, communications, biomedical, electronics and other fields. The study of dielectric complex dielectric constant measurement is particularly important. At the same time, with the development of computer technology, automatic measurement technology is more and more used in the field of microwave measurement. It is necessary to test the complex dielectric constant more efficiently in the measurement of complex dielectric constant. With the development of new materials, nanomaterials play a more and more important role in the field of microwave because of their unique characteristics. The study of dielectric properties of nanocrystalline materials has become a hot topic. In this paper, we use high order mode mode to measure complex dielectric constant, which is different from most methods of measuring complex dielectric constant. It is beneficial not only to observe the high frequency characteristics of dielectric properties of materials, but also to process and analyze the data. Based on the existing conditions in the laboratory, the rectangular resonator perturbation method is selected to measure the complex dielectric constant. At the same time, the electromagnetic simulation software HFSS is used to synthetically select the high order mode in the 0 ~ 3 GHz frequency band, and the mode analysis is carried out. Finally, the frequency point mode for testing is determined. Then, the formula for calculating complex dielectric constant of rectangular resonator perturbation method is derived. Based on LabVIEW2012, the automatic test software of complex dielectric constant is written, which can efficiently control the AV3620A vector network analyzer for testing. In order to verify the correctness and stability of the test system, the paper gives the test parameters needed in the actual test. The complex permittivity of polytetrafluoroethylene, resin glass and nylon has been tested. The accurate measurement of dielectric properties of some new microwave absorbing materials, such as carbon nanotubes (CNTs), has also been carried out step by step. In this paper, a novel method of mixing carbon nanotubes with liquid paraffin is used to prepare and measure the mixture. This approach improves the uniformity in the mixing process, This reduces the error in the process of sample preparation, increases the accuracy of the data, and tests the dielectric properties of the carbon nanotube / paraffin mixture with the developed automatic test system. The results show that it has good absorbing characteristics. Finally, a data correction of complex dielectric constant of non-standard samples based on HFSS simulation software is presented. For the test of complex dielectric constant of some non-standard samples, the data correction of high loss non-standard samples is verified by the method of combining experiment and simulation. The result shows that the difference between the complex dielectric constant of some non-standard samples and the standard value is small. It can be used as a reference for dielectric properties when standard measurement can not be carried out.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN015

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