消除校准源近场测量中杂散波的快速方法

Fast method of eliminating extraneous in near filed measurement of calibration load

提出了一种基于快速逆衍射算法对辐射计温度校准源的近场测量中的杂散波进行分析和消除的方法.逆衍射算法是利用测量场计算逆向传播到源平面处的衍射场的方法.基于直接积分的快速傅里叶转换(FFT-DI,Fast-Fourier-Transform Direct Integration)算法和衍射高斯波束分析(DGBA,Diffracted Gaussian Beam Analysis)算法与逆衍射算法相结合得到快速逆衍射算法.根据快速逆衍射算法提出了近场测量的分析步骤,并且给出了滤除杂散波后的被测物体的衍射场,其验证了该方法的有效性.此外,为了达到更高的效率,建议将2种快速逆衍射算法结合使用.

A method to analyze and eliminate the extraneous wave from near field measurement of the radiometer temperature calibration load based on fast inverse diffraction algorithm was presented. The inverse diffraction algorithm is used for field reconstruction by calculating the backward propagation of a diffraction field. Both the fast-Fourier-transform direct integration（FFT-DI） and diffracted Gaussian beam analysis（ DGBA） were implemented and combined with the inverse diffraction algorithm for fast inverse diffraction algorithm. An outline of the analysis on the near field measurement was presented, along with the filtered field without extraneous wave, which verifies the performance of this method. Furthermore, it was suggested that combination of these two fast inverse diffraction algorithm for higher efficiency.