电磁脉冲辐射波模拟器双锥-平面线栅天线场分布规律

双锥-平面线栅结构的水平极化辐射波天线对辐射场半宽影响较小且架设方便、易于维护，掌握该型天线场分布规律是确定模拟器场均匀区、开展电磁脉冲效应实验的前提。利用天线理论研究双锥-平面线栅天线的场分布规律，结合数值模拟和实际天线试验对理论分析结果进行验证。结果表明：在天线结构和激励电压确定的条件下，双锥中心正下方辐射电场极化分量仅与测点到源的距离相关，二者呈反比；Oxz平面内以双锥中心为圆心的圆弧上任意一点辐射电场极化分量的幅值相等，并在同一时刻达到峰值；Oxz平面内同一水平线上的测点总辐射场幅值相等，方向沿测点所在圆弧的切线方向；各辐射场分量关于Oxz平面和Oyz平面对称分布；对于实际模拟器，地面反射会使辐射场波形下降沿陡降，导致地面附近辐射场半宽变小；线栅极板会影响附近的场分布，且极板外侧4个角点处的反射相对较强，其他位置辐射场分布与理论分析一致。

Field Distribution of Biconical-wire Grating Antenna for Radiated-wave EMP Simulator

The horizontally polarized radiated-wave antenna with biconical-wire grating structure has less influence on the half-width of radiated E-field，and it is easy to erect and maintain. Mastering the E-field distribution rule is a premise to determine the simulator's uniform area and conduct the EMP effect experiment.The distribution rule of the radiated E-field is studied using the antenna theory，and the analysis results are verified by simulation and practical experiment.It shows that the polarized E-field component below the biconical apex is only inversely proportional to the distance from the observation point to the excitation source if the antenna structure and excitation voltage are determined.On Oxz plane，the polarized E-field amplitudes on a circle centered at the biconical apex are equal. And they reach the peak value at the same time.On Oxz plane，the total E-field amplitudes at the observation points on a horizontal line are equal，and their directions are along the tangent line of an arc where the observation points is located.The E-field components are symmetrical with Oxz and Oyz planes.As for a practical simulator，the ground reflection causes severe decline in the falling edge of the radiated E-field，which reduces the half-width of the radiated field near the ground. Meanwhile，the wire grating plate also affects the radiated field nearby，and the reflections are stronger at four angular points of the plate.The distribution of radiated fields at other points is consistent with theoretically analyzed result.