吴瑞荣 邹永庆 龙永刚 李景峰 吴贻伟

摘  要：文章提出了一种基于平面近场的有源相控阵天线系统G/T值测量方法，通过分别测量接收系统的有源增益和有源噪声功率，进而测量出G/T值。该方法在暗室平面近场进行，实现简单，受环境影响小，重复度高，解决了大型阵列天线G/T值测量困难的问题。给出了测量原理和测试误差分析，并通过对Ka频段接收相控阵的G/T值实测，与理论计算结果一致，且多次测量的抖动在0.25 dB内。

关键词：G/T值测量;有源相控阵天线;平面近场

中图分类号：TN82      文献标识码：A 文章编号：2096-4706（2021）01-0068-03

G/T Value Measurement Method of Active Phased Array System Based on

Planar Near Field

WU Ruirong，ZOU Yongqing，LONG Yonggang，LI Jingfeng，WU Yiwei

（The 38th Research Institute of China Electronics Technology Group Corporation，Hefei  230088，China）

Abstract：In this paper，a method of measuring G/T value of active phased array antenna system based on planar near field is proposed. By measuring the active gain and active noise power of the receiving system respectively，the G/T value can be measured. The method is implemented in the near field of the dark chamber plane，which is simple to realize，small affected by the environment and high repetition. It solves the difficult problem of measuring the G/T value of large array antenna. The measurement principle and error analysis are given in this paper. The measurement principle and error analysis are given. The measured G/T value of Ka band receiving phased array is consistent with the theoretical calculation，and the jitter of multiple measurements is within 0.25 dB.

Keywords：G/T value measurement;active phased array antenna;planar near field

0  引  言

有源相控陣天线因其具备波束指向、形状等灵活可变的高弹性，在测控通信、微波成像等多个领域广泛应用，随着芯片和微波集成技术发展，毫米波大型相控阵列得到长足应用。G/T值是接收有源相控阵系统参数中一项关键指标，是衡量接收相控阵灵敏度的质量指标，该指标高低意味着接收相控阵能否从噪声中识别信号。G/T值常用测试方法包含射电源法、卫星源法、远场法、紧缩场法等，这些测试方法均为搭建一个远场条件，利用弗里斯传输方程，通过测量系统等效全向发射功率EIRP、传输损耗、载噪比等，计算出G/T值。由于远场搭建耗时、费力，需要测试项目多，受环境影响大，造成G/T值测量耗费大，精度差。虽然紧缩场法在暗室内进行，受环境影响小，但紧缩场静区尺寸受制造成本制约，难以提高，特别是针对毫米波等高频段的应用。

本文提出了一种基于平面近场的有源相控阵天线系统G/T值测量方法，针对有源相控阵天线G/T值测量面临的问题，提出了利用平面近场暗室分别测量出接收系统的有源增益和有源噪声功率，通过两者相比得出G/T值的方法。……