在对空气-地面分层媒质中微波传播与反射理论分析的基础上,研究了地面反射对测点处不同垂直高度电场分布的影响,推导得到了电场分布随垂直高度变化曲线的振荡周期理论计算公式,针对高功率微波源总功率测量,提出了一种双天线阵列抑制地面反射影响的高功率微波辐射场测量方法,通过数值计算、低功率连续波实验、大功率短脉冲实验等进一步验证了理论公式的正确性,以及双天线阵列抑制地面反射影响方法的可行性。结果表明,与单接收天线相比,双天线阵列法可将地面反射影响由原有的4 dB降低至0.6 dB以下,从而有效减小了高功率微波辐射场的测量不确定度,为高功率微波源总功率准确测量奠定了基础。

This paper presents a new measuring method of minimizing the impact of ground reflection on the microwave electronic field measurement using double antenna array. The character of ground reflection is studied using the electromagnetic geometric optics theory and the electromagnetic wave propagation formula in layered media. Then a theoretical formula for computing the oscillating period of ground scattering pattern is derived. The impact of ground reflection on the transversal field and vertical field is simulated using the FDTD method, and the effect of minimizing the ground reflection with double antenna array is also validated by simulation, it shows that the impact of ground reflection is decreased from 4 dB to less than 0.6 dB, which improves the accuracy of the high power microwave radiation field measurement.