This paper presents a method of reconstructing far-field characteristics by using phaseless spherical near-field measurement, which is used to solve insufficient phase information problem in the near-field measurement of the antenna under test. This method firstly samples the amplitude of two spherical surfaces with different radius in the near-field region, and then iteratively recovers the phase of a sampling spherical electric field based on the spherical wave expansion (SWE) method of spherical near-field measurement. Finally, the far-field data is calculated by combining the simulation near-field measurement amplitude and recovered phase. In this paper, we compare the far-field results of near-far field transform algorithm and phaseless spherical algorithm with different sampling intervals and analyze the error of phaseless spherical algorithm. Then, an improved method of reducing SWE order is proposed. The simulation results show that the far-field characteristics of the antenna can be calculated effectively by adjusting the SWE order.

本文提出了一种利用无相位球面近场测量重建远场特性的方法，用于解决被测天线近场测量中相位信息不足的问题。该方法首先在近场区域对两个半径不同的球面的振幅进行采样，然后基于球面近场测量的球面波展开法（SWE）迭代地恢复采样球面电场的相位。最后，结合模拟近场测量幅度和恢复相位，计算出远场数据。在本文中，我们比较了不同采样间隔的近场变换算法和无相球面算法的远场结果，分析了无相球面算法的误差。然后，提出了一种降低SWE阶数的改进方法。仿真结果表明，通过调整SWE阶数可以有效地计算出天线的远场特性。