基于RPIM 法的圆极化天线特性参数快速测试

为提高圆极化天线特性参数的测试精度,线极化分量法往往需要对线分量场进行多次测量。文中在天线测试系统中引入插值算法,减少采样点,提高圆极化天线测试效率。将径向基函数的点插值无网格(RPIM)法引入圆极化天线参数合成算法中,首先使用RPIM 拟合出测试场的幅值和相位,然后再使用解析的方式合成圆极化天线的轴比和方向图,算法性能与基于分段线性插值技术的模型参数估计法(MBPE)和基于三次样条插值的移动最小二乘法(MLS)进行比较,数值实验显示,当采样点数仅为测试点数的4%时,MLS 失效,MBPE 和RPIM 误差均为10-3量级;而当采样点数减少为测试点数的2%时,MBPE 和MLS 均失效,RPIM 的误差虽然增大到10-1 量级,但仍能保持稳定。数值实验证明,在采样点数较少情况下,RPIM 性能优于其它两种算法。

Fast Measurement of a Circularly Polarized Antenna Based on RPIM Method

In order to improve the measurement accuracy of the characteristic parameters of a circularly polarized antenna, the linear polarization component method often needs to measure the linear component field several times. The interpolation algorithm is introduced into the antenna test system to reduce sampling points and improve the test efficiency of circularly polarized antenna. Radial Point Interpolation Meshless (RPIM) technique is introduced into the parameter synthesis algorithm of circularly polarized antenna. First, the RPIM technique is used to fit the amplitude and phase of the test field, and then the axial ratio and pattern of the circularly polarized antenna are synthesized in an analytic method. The performance of the algorithm is compared with the Model Based Parameter Estimation (MBPE) method based on piecewise linear interpolation technique and the Moving Least Square (MLS) method based on cubic spline interpolation, the numerical experiments show that when the sampling points are 4% of the test points, MLS fails, and the errors of MBPE and RPIM are at the order of 10-3 , when the sampling points are reduced to 2% of the test points, both MBPE and MLS fail, although the errors of RPIM increase to the order of 10-1 , it remains stable. The numerical experiments show that RPIM outperforms the other two algorithms in the case of a small number of sampling points.