This article introduces a low-cost time-domain near-field measurement system based on softwaredefined radio (SDR). The method is based on using a low-cost receiver to retrieve by Fourier techniques the amplitude and phase of the signal radiated by antennas. The uncertainties introduced by the receiver are modeled and compared with empirical data. Moreover, a setup based on a reference antenna is explored as a possible solution to fix the phase reference of the measurement. The limitations and optimization of the setup are analyzed for different geometries. Some postprocessing techniques are demonstrated to be suitable to overcome the inherent errors introduced by the setup. Once the amplitude and phase are recovered, diagnostic techniques or near-field to far-field transformation can be applied. The results demonstrate the potential and good accuracy of the method for fast and lowcost characterization of antennas when the reference is not accessible.

中文翻译：

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一种基于软件定义无线电的无参考天线测量系统【测量角】

本文介绍了一种基于软件定义无线电（SDR）的低成本时域近场测量系统。该方法基于使用低成本接收器通过傅立叶技术检索天线辐射信号的幅度和相位。接收机引入的不确定性被建模并与经验数据进行比较。此外，探索了基于参考天线的设置作为固定测量相位参考的可能解决方案。针对不同的几何形状分析了设置的限制和优化。一些后处理技术被证明适用于克服设置引入的固有错误。一旦恢复了幅度和相位，就可以应用诊断技术或近场到远场的转换。