Cryogenic 0.7-4 GHz Eleven Feed for Changbai Mountain Telescope

Paper in proceeding, 2026

To enhance the observational performance of the 40-meter radio telescope at Changbai Mountain and to support related astronomical research, this paper proposes a cryogenic dual polarized Eleven feed operating the 0.7-4GHz frequency band. The feed is excited through coaxial lines, with one port for each polarization, which significantly reduces the structural complexity of the feed system. Simulation results indicate that within the operating frequency band, the total feed efficiency exceeds 55% and the reflection coefficient is generally less than -10 dB, demonstrating excellent electrical performance and meeting the high-precision observation requirements of the telescope.