Design of a Wide Angle Horn Feed at Main Focus

In this paper, a wide angle horn feed at main focus working in the frequency of 22-33 GHz is designed. The corrugated structure is adopted. The corrugated structure equally arranged in the same direction as the circular waveguide is loaded outside the circular waveguide. The loaded corrugated structure is composed of loaded slots and rings. The number of loaded rings and slots is all 15. The feed is used for the main focus irradiation of the 2m reflector antenna. The design opening angle is 112°, the E-plane pattern gain at the working frequency points of 23.8 and 31.2 GHz is 48.3 and 48.4 dBi respectively, the half power beam width is all 0.2°, and the side lobe levels are - 40.3 and - 33.5dB respectively, which meet the design requirements. Subsequently, the processing and measurement of the horn feed will be carried out, so that it can be applied to the atmospheric opacity measurement system of 2m radio telescope.