平面近场测量的共轭梯度法分析

从被测天线(AUT)和探头的耦合方程出发，利用Nyquist定理，推导出了扫描面上近场和波谱函数之间的矩阵方程。用共轭梯度法(CG)求解这一矩阵方程，得到波谱函数，从而算出远场方向图。这种方法只需要知道测量点的位置就足够，并不要求测量点必须位于某些特定点上。计算结果表明，用此方法原理上可消除常规平面近场测量中位置误差的影响。

Analysis of Planar Near-Field Measurement Using Conjugate Gradient Method

A matrix equation relating near field on the planar surface with spectrum function is deduced by using Nyquist theorem, based on the coupling functions between the AUT and probe. The spectrum function is obtained by resolving the matrix equation using conjugate gradient method,and thus the pattern can be gained. This method only requires to know the positions of measurement points, and don't require that the measurement points must be at specific positions. The calculated results show that the effect of position error in the planar near field measurement can be removed efficiently.