垂直极化辐射波EMP模拟器辐射场空间分布特性分析

Analysis of Spatial Distribution Characteristics of Radiation Field in Vertically Polarized EMP Simulator

针对垂直极化辐射波电磁脉冲(electromagnetic pulse,EMP)模拟器有效工作空间选择的问题,利用轴对称柱坐标系中的并行时域有限差分(finite-difference time-domain,FDTD)方法,模拟研究了垂直极化辐射波EMP模拟器辐射场空间分布特性。首先,模拟分析了模拟器的架高和半锥角对辐射场垂直分量峰值的空间分布及对“辐射场垂直分量的上升沿和半高宽均满足IEC标准”测点的空间分布的影响;然后对模拟器辐射场径向分量峰值与垂直分量峰值比值的空间分布特性进行了讨论;最后以架高为8 m、半锥角为32°的模拟器为例,给出了模拟器有效工作空间的选择方式。模拟结果表明:金属底板上的所有测点辐射场的垂直分量峰值均基本随测点与中轴线的距离的增加而减小;在一定高度范围内,同一测点辐射场的垂直分量峰值不会随模拟器架高的变化而变化,但会随模拟器半锥角的增加而增加;“辐射场垂直分量的上升沿和半高宽满足IEC标准”的空间区域随模拟器架高的增加而增加;在一定高度范围内,同一测点辐射场径向分量的峰值与垂直分量峰值之比约等于该测点的高度与该测点与中轴线的距离之比;测点在高度上越靠近金属底板,测点辐射场的垂直分量所占主导地位越明显;可根据效应物的尺寸来选择合适的模拟器有效测试空间。

In this paper,the parallel finite-difference time-domain(FDTD)method in the axisymmetric cylindrical coordinate system is used to simulate and study the spatial distribution characteristics of the radiation field of the vertically polarized radiating-wave electromagnetic pulse(EMP)simulator.Firstly,the effects of the height and the half cone angle of the simulator on the spatial distribution of the peak value of the vertical component of the radiation field and the spatial distribution of the measuring points where the rise-time and FWHM of the vertical component of the radiation field meet the IEC standard are simulated and analyzed.Then,the spatial distribution characteristics of the ratio of the radial component peak to the vertical one of the radiation field are discussed.Finally,taking the simulator with height of 8 m and half cone angle of 32°as an example,the selection of effective working space of the simulator is given.The simulation results show that the peak value of the vertical component of the radiation field at all measuring points on the metal base plate decreases with the increase of the distance between the measuring points and the central axis.Within a certain height range,the peak value of the vertical component of the radiation field at the same measuring point will not change with the height of the simulator,but will increase with the increase of the half cone angel of the simulator.With the increase of the height of the simulator,the space domain of“the rise-time and the FWHM of the vertical component of the radiation field meet the IEC standard”increases,and the ratio of the peak value of the radial component to the peak value of the vertical component of the radiation field at the same measuring point is nearly equal to the ratio of the height of the measuring point to the distance between the measuring point and the central axis.The closer the measuring point is to the metal pad,the more dominant the vertical component of the radiation field is.Therefore,the area of the effective test space of the simulator can be selected according to the size of the test object.