Antenna Noise Temperature of the Feed System for Shanghai VGOS Radio Telescope

The demand for higher precision measurements in Very Long Baseline Interferometry (VLBI) continues to grow, which drives the technical development of next-generation international VLBI stations called the VLBI Global Observing System (VGOS). We have measured the noise temperature of the wideband receiving system for Shanghai VGOS telescopes by generally the Y-factor method, which is to place the hot load in front of the feed then to let the system point to the cold sky. Shanghai VGOS telescopes, with a diameter of 13.2 m, works in the 3–18 GHz range with dual-linear polarization and is based on the ring focus reflector principle. Removing signal interference points, in the whole broadband range, the noise temperature of the receiver system is lower than 40 k.