Electromagnetic analysis and preliminary commissioning results of the shaped dual-reflector 32-m Ghana radio telescope

IEEE Radio and Antenna Days of the Indian Ocean 2017

无线电电子学

Venter, M.^1 ; Bolli, P.^2

SKA South Africa, Pinelands

7405, South Africa^1

INAF-Arcetri Astrophysical Observatory, Firenze

50125, Italy^2

关键词: Aperture efficiency;    Astronomical observation;    Electromagnetic analysis;    Electromagnetic software;    Mechanical tolerances;    Operating frequency;    Shaped reflector;    Slanted beams;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/321/1/012003/pdf
DOI  :  10.1088/1757-899X/321/1/012003

来源: IOP

【 摘 要 】

This paper presents results from the electromagnetic analysis of the African VLBI Network shaped Ghana radio telescope at the operating frequencies of 5 and 6.7 GHz. The geometry implemented in commercial electromagnetic software provides insight into the effects of the slanted beam-waveguide, shaped reflector illumination and mechanical tolerances, which are known to be more stringent compared to a perfect paraboloid. It is shown that the theoretical maximum gain and aperture efficiency at 5 GHz are 63.80 dBi and 85.45%, respectively. The corresponding values at 6.7 GHz are 66.47 dBi and 88.00%, respectively. Comparisons to sidelobe maps produced from astronomical observations are also discussed, showing possible misalignment in the structure when utilised outside its originally intended purpose.