基于FFT的近场-口径场变换方法

A Transformation Technique from Near Field to Aperture-Field Based on FFT

本文提出的近场 -口径场变换方法基于探头与被测天线 (AUT)的耦合方程 ,由Fourier变换求出 AUT发射场的平面波谱的切向分量 ,然后由 Fourier反变换求出被测天线口径场的切向分量 ,从而达到诊断天线口径场幅相分布的目的。口径场变换中的大部分计算采用 FFT算法 ,并且引入空间域的重构法 ,数值精度好 ,数据处理效率高 ,可以达到任意的诊断分辨率。通过数值模拟和诊断实验 ,说明了该方法的正确性和工程实用性。

The present trnsformation from near field to aperture field is based on the coupling equation of the probe and the antenna under test (AUT). The tangential components of planar spectra are determined by Fourier transform, then the tangential components of aperture fields are found by inverse Fourier transform for the purpose of diagnosing amplitude phase distribution of aperture field of AUT. A large amount of calculation in the transformation of aperture fields is performed by FFT with accurate numerical results and efficient data processing. An introduction of the spatial domain reconstruction method makes this technique obtain any diagnostic resolution. Through numerical simulation and diagnostic experiment,this technique proves to be accurate and practical.