基于间接时域测量的窄带天线误差修正方法研究

针对间接时域测量技术在测量低频窄带天线时扫频带宽窄,距离分辨率低,在时域无法精确加门去除多径干扰的问题,引入一种新的拓展测试带宽的方法,即使扫频带宽远大于天线的工作带宽,利用反射系数将天线反射回馈线的功率补偿到频域响应上,虚拟天线在整个扫频带宽内无反射,通过傅里叶变换及加时域门的方法可以获得精确的方向图;对所提出的方法进行了实验验证,结果表明经过反射系数的补偿修正,距离分辨率得到提高,测试误差减小了1.8dB,所得到的方向图与标准方向图更为接近。

Research of Correction Techniques of Narrow-band Antenna Based on Indirect Time-domain Measurement

Time-domain measurements are shown to be impractical for a lower frequency antenna,especially a narrow-bandwidth antenna inside an anechoic chamber and cannot be used to get rid of the multi-path interferences because of the lower range resolution.A new method of bandwidth expansion has been introduced,which set the sweep bandwidth is much larger than the operating bandwidth,compensate the frequency domain response with the power reflected to transmission line and transforms the frequency domain response into time domain using a Fourier transform,then the reflections from the environment can be filtered out by imposing a gating window.The method is investigated by both analytical and experimental methods.The results show that the range solution has been improved and the measurement error can be reduced by 1.8dB,the pattern compensated by reflection coefficient is close to the standard radiation pattern.