基于地-线缆耦合的感应电流分析*
Induced Current Analysis Based on Ground鄄Cable Coupling
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摘要: 高功率、大强度电磁波照射,是飞机在电子对抗中实施电磁干扰的重要手段。在实验室通过电流钳对线缆进行电流注入,从而达到模拟飞机系统间电磁干扰试验的目的。如何从理论上分析照射场在电缆上所感应的电流,是飞机系统间抗扰度实验的重要环节。文章利用有源传输线理论,建立了线缆鄄大地耦合模型,给出了线缆电流分布与大地电导率、地-线缆高度、线缆长度、线缆两端阻抗以及照射场的频率、幅度等多参数的关系;同时还进行了实测验证。结果表明,理论分析与实测结果基本一致,这为飞机系统间电磁干扰试验的实施提供了必要的理论和数据基础。Abstract: High power density electromagnetic radiation is an important means in aircraft electronic countermeasures. The test can be carried out by BCI (Bulk current injection) or DCI (direct current injection) technique. How to obtain the current distribution in the cable theoretically is an important part in the immunity test. In this paper, the transmission line with a distributed source model has been applied to the ground-cable coupling problems, the relationship of the cable current distribution with ground conductivity, ground-cable height, the cable length, impedances of the cable ends and the frequency and amplitude of radiation field was given. Comparison shows that the current distribution of the calculation has a consistency of ±5dB with measured value, this validity of the model can offer a way to value the induced current in BCI or DCI.