Resumo

KUJA, S.  e  WIID, P. G.. Computational modelling for dish-to-dish coupling investigations on MeerKAT telescope. SAIEE ARJ [online]. 2018, vol.109, n.1, pp.69-77. ISSN 1991-1696.

The MeerKAT telescope will form part of the Square Kilometre Array (SKA) which will have orders of magnitude greater sensitivity than existing radio telescopes. Radio Frequency Interference (RFI) poses a great threat to such sensitive equipment. We characterize electromagnetic (EM) signals on a single dish structure using a physical scale model, computational electromagnetic (CEM) modelling and field measurement. The CEM code and method of moments frequency domain numerical technique are utilised throughout the study. We successfully achieve CEM model verification through measurement of a physical scale model in an anechoic chamber. The validated model is further verified with full scale on-site measurements. A transfer function determined from an incident electric field and the associated induced currents on various cables of a single dish structure is used to compare simulation and measurement. We use our corroborated CEM model to investigate dish to dish coupling in order to predict whether the MeerKAT system would be at risk. With a low power radiation of -70 dBm from a neighbouring dish, we predict coupled power of less than -120 dBm to the nearest dish.

Palavras-chave : Anechoic chamber; computational electromagnetic (CEM) modelling; dish to dish coupling; method of moments; radio frequency interference (RFI); telescope; transfer function.

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