基于外场场强测量的短波天线辐射效率监测

Monitoring of Short-wave Antenna Radiation Efficiency Based on Outfield Measurement

针对短波天线辐射效率难以现场监测的问题,研究一种基于外场场强测量的短波天线辐射效率监测方法。该方法结合天线仿真与测量技术,通过域变换法解析介质半空间位型并矢格林函数,采用RWG矩量法(RWG-MoM)离散平面分层介质C类混合位电场积分方程(MPIE),得到天线辐射功率的相对分布。测量天线外场场强,得到场点电磁功率面密度作为样本估计天线辐射功率,由辐射功率与输入功率的比值计算得到天线辐射效率。以短波双极天线为例,基于现有的飞艇场强测量平台,进行室外远场场强的测量,实验得到的归一化场强方向图与仿真结果吻合较好,通过该方法计算得到的天线辐射效率与公开文献一致性较好,实现了短波天线辐射效率的监测。

Aiming at the problem of too many difficulties to monitor the radiation efficiency of short-wave antennas on site,a method based on outfield measurement of field strength to monitor the short-wave antennas＇radiation efficiency was researched.This method combined technologies of antenna modeling and measurement,solved and analyzed the potential-type dyadic Green＇s function of medium half space by the domain-transformation method.The RWG Method of Moment （RWG-MoM）was adopted to discrete the Mixed Potential Integral Equation （MPIE）in formulation C of planar multi-lay-ered media,and the relative distribution of short-wave antenna radiation power was obtained.The outfield antenna radiation field strength was measured to get the real density of electromagnetic power,which was made as the sample to estimate the antenna radiation power,and the radiation efficiency was calculated by the ratio of the radiation power and the input power. And then,taking short-wave dipole antenna as example,the measurement of field strength in far field was conducted by air-ship field strength measuring platform,and the normalized radiation patterns obtained in experiments were in good agree-ment with simulation.The radiation efficiency calculated by this method coincided well with published papers＇,and the moni-toring of short-wave antennas＇radiation efficiency was achieved.