多径效应对机载干涉仪天线的影响及措施分析

Research and measures of multipath effect on airborne interferometer antenna

干涉仪测向是一种具有较高测量精度的测向方法,广泛应用于机载无源探测系统。由于装机后机体和天线相互作用,导致天线的电性能参数变化较大,因此需要在装机条件下对天线的幅度和相位进行校准。限于实际测试条件,通常需要在地面进行实验,而地面的多径效应对校准有较大影响。分析了多径效应对干涉仪天线阵幅度和通道间相位差的影响,并和实验结果进行了验证对比。分析表明在反射点位置放置吸波材料可有效降低多径效应的影响。

Interferometer direction-finding is a method with high measurement accuracy, and widely used in airborne passive detection systems. However,the interactions between the aircraft and antennas lead to a large change in the electrical properties. Therefore,it is necessary to calibrate the amplitude and phase of the antennas. Subject to test conditions,experiments are usually done on the ground, the multipath effect has a greater impact on calibration. The influence of multipath effect on the amplitude and phase of the interferometer antenna array is analyzed and compared with the experiment. Analysis shows that placing absorbing materials at the reflection point can effectively reduce the effects of multipath effects.