新一代射电望远镜接收系统向着集更宽的工作带宽、更高的灵敏度、更大的观测视场和更快的巡天速度于一体的高综合性能方向发展。兼具宽带和高灵敏度的相控阵馈源（Phased Array Feed,PAF）作为射电天文高性能馈源的发展趋势，有望纠正反射面的形变和指向带来的相差，提高天线效率，抑制射频干扰，消除馈源支撑近场散射引起的驻波，有利于大型射电望远镜的大天区连续扫描与快速巡天观测。.本课题以大型射电望远镜FAST为依托，首次开展面向FAST的宽带（700MHz-1.5GHz）高灵敏度相控阵馈源的系统设计方案的研究，解决宽带PAF低噪声阵列硬件设计、复杂环境下数字波束合成方向图综合算法以及PAF系统性能评估方面的关键问题和技术瓶颈。完成第一代常温宽带低噪声PAF系统原理样机的系统仿真分析和观测实验验证。为未来FAST L波段宽带高灵敏度相控阵馈源系统的全面研制奠定坚实的理论和实验基础。

The new generation of receiver system for radio telescope is developing towards a high comprehensive performance of broader working bandwidth, higher sensitivity and larger field of view as well as faster survey speed. The phased array feed (PAF) with both broadband and high sensitivity will be the development trend of high performance feed for radio astronomy in the future. It is hopeful to correct the Coma effect caused by the deformation and direction errors of the reflector, improve the antenna efficiency, eliminate radio frequency interference and suppress standing wave caused by near-field scattering of the feed cabin so as to speed up continuous scanning and survey of large sky area for large radio telescopes.. The design scheme of broadband (700 MHz-1.5 GHz) high-sensitivity phased array feed system for FAST will be studied in this project. We will focus on key technologies in the hardware design of wide-band PAF low-noise array, the synthesis algorithm of digital beam synthesis pattern in complex environment and the performance evaluation of PAF system. The system simulation analysis and experimental verification of the first broadband low-noise PAF system prototype at room temperature will be carried out. The proposed research will set up solid foundation both theoretically and experimentally for future development of the FAST L-band broadband phased array feed system.