半电波暗室的低频性能研究

发布时间：2019-01-07 07:53

【摘要】：随着无线通信技术的不断发展与应用,电子电气产品与系统的电磁兼容性问题显得尤为重要。作为电磁兼容测试系统的重要组成部分—半电波暗室发挥着不可替代的作用。同时,半电波暗室的性能也受到了越来越多的关注,特别是随着工作在低频段的电气电子设备和系统的数量不断增加,半电波暗室的低频性能对于准确评估其电磁兼容性起到了关键性的作用,因此,对半电波暗室的低频性能研究具有重要的意义和广阔的应用前景。本文围绕半电波暗室的性能指标—场均匀性和归一化场地衰减在低频段的特性展开研究。主要内容如下:(1)基于铁氧体与屏蔽室的特性分析,采用外推拟合的方法,得到了10kHz～30MHz频段内铁氧体的电磁参数,并理论分析了铁氧体的吸波特性。以二阶色散模型在软件中进行材料参数的设置,仿真分析了铁氧体的反射率,根据理论、仿真和实测对比了铁氧体的吸波特性,从侧面验证数据的可行性。同时,对屏蔽暗室的谐振特性进行了分析,并通过仿真分析可知,铁氧体能够抑制屏蔽室的谐振,使半电波暗室在低频段能够很好的模拟开阔场。(2)针对场均匀性的研究,阐述了实验原理与方法,根据场均匀性测试方法建立了暗室场均匀性的模型,分析对比了铺设铁氧体前后的暗室的场强分布,运用FDTD算法对暗室的场均匀性进行了仿真分析,并与某暗室内场均匀性的实测值进行了对比分析,结果表明仿真与实测值基本吻合。(3)对于NSA的研究,根据实验原理与方法,采用场地参考法对NSA运用FDTD算法进行了仿真分析。同时,进行了实测对比,对比结果表明,仿真与实测是吻合的,误差是在可接受的范围内。
[Abstract]:With the development and application of wireless communication technology, the electromagnetic compatibility of electronic and electrical products and systems is becoming more and more important. As an important part of electromagnetic compatibility testing system, half-wave anechoic chamber plays an irreplaceable role. At the same time, more and more attention has been paid to the performance of half-wave anechoic cells, especially with the increasing number of electrical and electronic devices and systems working in low frequency band. The low-frequency performance of the half-wave anechoic chamber plays a key role in accurately evaluating its electromagnetic compatibility. Therefore, it is of great significance and broad application prospect to study the low-frequency performance of the half-wave anechoic cell. In this paper, the field uniformity and the characteristic of normalized site attenuation in low frequency band are studied. The main contents are as follows: (1) based on the characteristic analysis of ferrite and shielding chamber, the electromagnetic parameters of ferrite in 10kHz~30MHz band are obtained by extrapolation fitting method, and the wave absorption characteristics of ferrite are analyzed theoretically. The second order dispersion model is used to set the material parameters in the software, and the reflectivity of ferrite is simulated and analyzed. According to the theory, the characteristics of absorbing wave of ferrite are compared with the measured data, and the feasibility of the data is verified from the side. At the same time, the resonant characteristics of the shielded chamber are analyzed, and the simulation results show that the ferrite can suppress the resonance of the shielding chamber, so that the semi-anechoic chamber can well simulate the open field at low frequency. (2) the research on field uniformity. The experiment principle and method are expounded, the model of field uniformity of dark chamber is established according to the test method of field uniformity, the field intensity distribution of dark chamber before and after laying ferrite is analyzed and the field uniformity of dark chamber is simulated by FDTD algorithm. The results show that the simulation results are in good agreement with the measured values. (3) for the study of NSA, according to the experimental principle and method, The field reference method is used to simulate NSA using FDTD algorithm. At the same time, the experimental results show that the simulation is consistent with the actual measurement, and the error is within the acceptable range.
【学位授予单位】：南京信息工程大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN03

【参考文献】