辐射式核电磁脉冲模拟器TEM喇叭天线

针对辐射式核电磁脉冲模拟器采用TEM喇叭天线作为辐射天线时低频辐射能力有限的问题，对板型和线型两种基本形式的TEM喇叭天线进行了分析。在采用线型TEM喇叭天线以减轻模拟器重量的基础上，在天线末端采用螺旋线结构，并增加屏蔽板回路，构造了一种新型TEM喇叭天线。结果表明：与普通线型TEM喇叭天线相比，该新型天线较大地提高了低频辐射性能，可使近场波形脉宽提高7 ns左右，峰值场强提高了1 kV/m左右；通过增大螺旋线半径和提高螺旋线密度可以提高峰值场强，增加近场波形脉宽；通过屏蔽板回路可以降低反射波纹的波峰从而改善近场波形。

Analysis of TEM horn antenna for radiating-wave nuclear electromagnetic pulse simulator

For the problem that TEM horn antenna used in the radiating-wave nuclear electromagnetic pulse (NEMP) simulator has limited ability of low frequency radiating, two basic types of TEM horn antennas (composed of plates and wires respectively) are analyzed. Based on TEM horn antenna composed of wires that can make simulator lighter, a new type of TEM horn antenna is designed by using the structure of helixes end and attaching the shielded plates circuit to antenna. Results show that compared with the common type of the TEM horn antenna composed of wires, this new type of antenna has improved the ability of low frequency radiating greatly. The pulse width of near field waveform is longer by almost seven nanoseconds, and the peak value of pulse is larger by almost one kilovolt per meter. Increasing the radius of helixes and decreasing the pitch of helixes can further enhance both pulse width and peak value of the field strength. Meanwhile, attaching the shielded plates circuit to antenna can further lower down the wave crest generated by reflected signals, which makes the near field waveforms much better.