# Development and Research of a Medium Vertical Dipole Electromagnetic Pulse Simulator
## 4 Experiments and Characteristics Research
### Conclusions  
The following conclusions can be drawn from the above experiments and analysis:  
1. The radiation field waveform generated by the developed simulator has a front edge between 2 and 3 ns, a half-width of about 25 ns, and meets the requirements of the EMP test standard. It can be used to carry out EMP-related experimental research. Due to the discontinuity of the actual antenna structure, there will be some distortion in the radiation field waveform compared to the ideal double exponential high-voltage pulse signal fed from the driving source. However, it will not have a significant impact on the important indicators of the radiation field waveform, such as the front edge and the half-width.
2. The amplitude of the electromagnetic radiation field at the same measuring point around the wire grid antenna will gradually decrease as the number of antenna cables decreases. When the number of cables is reduced to less than 12, the radiation field waveform will undergo severe distortion and no longer meet the requirements of the test standard. When the number of the antenna cables is set to 24 or above, the radiation field waveform remains basically unchanged.
3. The electromagnetic radiation field generated by the ideal inverted cone antenna will have an isotropic distribution along the circumference, with the vertex of the cone as the center. Along the radial direction, the amplitude of the radiation field will decay according to the 1/r rule as the monitor moves away from the conical point of the antenna, while the waveforms of the radiation field remain unchanged. However, in the actual engineering implementation process, due to the presence of the support system, there may be some differences in the radiation field waveform at different angles on the same circumference and at different distances near the support column, but this does not affect the main parameters of the radiation field, such as the front edge and half-width.
4. When the current wave fed into the antenna reaches the top of the inverted cone antenna and the outer edge of the conductive plane on the ground, it will cause a distortion of the radiation field waveform due to the sudden change in the conductive impedance. When the measuring point is far away from these two locations, this distortion mainly manifests itself in the trailing edge of the radiation field waveform, with little effect on its leading edge and half-width. Therefore, when the antenna end is treated with three different methods of grounded-nearly, grounded-distantly, and open-ended, the radiation field waveform in the test area is basically unaffected, only slightly different at its trailing edge. The loading resistance on the antenna cable can reduce the impact of the reflection caused by the structural discontinuities on the radiation field waveform. However, selecting a resistance value that is too large may cause a decrease in the amplitude of the radiation field or even severe waveform distortion. Therefore, when using this method, sufficient argumentation is required.