基于横电磁波天线的高空核电磁脉冲辐射波模拟器设计

Design of HEMP Radiating-wave Simulator Based on TEM Horn

为解决传统核电磁脉冲模拟器存在测试空间受限的问题,提出了基于横电磁波(TEM)喇叭天线的高空核电磁脉冲辐射波模拟器设计方案。通过数值仿真验证了TEM喇叭天线的辐射场波形,指出TEM喇叭天线在应用于辐射式电磁脉冲模拟器时存在低频辐射能力差的问题;通过比较TEM喇叭天线对3种典型核电磁脉冲的辐射能力,发现辐射场的上升沿部分主要取决于激励源的上升前沿陡度,辐射场的脉冲宽度与激励脉冲的宽度有关,可以通过展宽激励源脉冲宽度的方法来补偿TEM天线低频辐射能力差的问题;通过实验验证了利用TEM喇叭天线研制电磁脉冲辐射波模拟器的可行性,但仍需要阻性加载或展宽激励脉冲等方法对TEM喇叭天线的低频辐射性能进行改善。

A TEM horn antenna of HEMP radiating-wave simulator is presented to expand the relatively small testing zone of the traditional transmission line simulator. The radiation field waveform of the antenna is simulated. The simulation results show that TEM antenna can be used to radiate HEMP simulation radiating wave, but in low frequency band its emissive capability is poor. Compared with radiation field waveforms of three typical HEMP excitation sources, it is concluded that the rise edge of the radiation waveform is determined by the changing rate of the excitation pulse source＇s rise edge, and the width of the radiation waveform is determined by the width of the excitation pulse. So the impact of the low frequency radiation capability deficiency can be compensated by expanding the excitation pulse width. The idea of using TEM horn antenna for HEMP radiating-wave simulater is verified by experiments. However, this application still needs improvement in the antenna＇s low frequency radiation capability, by means of loading resistance and expanding the exciation pulse width etc.