Research progress on design of high-performance phased array cryogenic receiver

<p indent="0mm">This article is based on the National Key Research and Development Program. It provides a comprehensive overview of the current status of phased array feed (PAF) research both domestically and internationally, highlighting the significance of phased array cryogenic receivers. The research team aims to design a cryogenic receiver for the QiTai 110-meter Radio Telescope (QTT). The proposed system is divided into three subsystems: the cryogenic phased array feed subsystem, the RF transmission subsystem, and the digital signal processing subsystem. This paper details the preliminary design and progress of each subsystem. The theoretical analysis demonstrates that the designed receiver meets the target specifications, including an operating frequency of <sc>0.7–1.8 GHz,</sc> an aperture efficiency ≥65% (QTT), an instantaneous bandwidth of <sc>500 MHz,</sc> dual linear polarization, and a system noise temperature <sc>≤20 K.</sc>