明安图射电频谱日像仪是新一代太阳专用射电成像望远镜,超宽带双圆极化接收馈源是其关键技术之一.轴比是反映双圆极化馈源性能的重要指标,单天线测量轴比的传统方法需要标准天线辅助,本文采用基于相关测量干涉阵馈源轴比的方法,针对MUSER天线数目多,且为户外环境,根据天文观测的需求须经常测试天线的性能的特点,简化了干涉阵望远镜测量轴比的过程,且能够高效的得到准确的测量结果.文中对该方法的测量过程做了详细的说明,给出了部分天线的测试结果,结果同时反映了馈源的良好特性.
The MUSER( Mingantu Sp Ectral Radioheliograph) is a newgeneration of solar dedicated radio telescope.Its ultra-wide band dual-circular polarized feed is one of the key technologies. AR( Axis Ratio) is an important parameter for measuring feed efficiency. The traditional AR measurement needs the involvement of the standard antenna. In this paper,the method by measuring correlation is adopted to measure AR of feeds for MUSER. Since MUSER has numbers of antennas and located in harsh environments,according to the demand of astronomical observations,the performance of the antennas should be measured frequently. This method simplifies the process of AR measurement of the interferometric array and can obtain accurate results efficiently. The measuring process are presented in detail in this paper. In addition,the results of AR measurement showthe favourable characteristics of the feeds for MUSER.