Spectral performance of SKA log-periodic antennas I: Mitigating spectral artefacts in SKA1-LOW 21 cm cosmology experiments
bij de Vaate, JG
Monthly Notices of the Royal Astronomical Society
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De Lera Acedo, E., Trott, C., Wayth, R., Fagnoni, N., Bernardi, G., Wakley, B., Koopmans, L., et al. (2017). Spectral performance of SKA log-periodic antennas I: Mitigating spectral artefacts in SKA1-LOW 21 cm cosmology experiments. Monthly Notices of the Royal Astronomical Society, 469 (3)https://doi.org/10.1093/mnras/stx904
© 2017 The Authors. This paper is the first in a series of papers describing the impact of antenna instrumental artefacts on the 21 cm cosmology experiments to be carried out by the low frequency instrument (SKA1-LOW) of the Square Kilometre Array telescope (SKA), i.e. the Cosmic Dawn (CD) and the Epoch of Reionization (EoR). The smoothness of the passband response of the current log-periodic antenna being developed for the SKA1-LOW is analysed using numerical electromagnetic simulations. The amplitude variations over the frequency range are characterized using low-order polynomials defined locally, in order to study the impact of the passband smoothness in the instrument calibration and CD/EoR Science. A solution is offered to correct a fast ripple found at 60 MHz during a test campaign at the SKA site at the Murchison Radioastronomy Observatory, Western Australia in 2015 September with a minor impact on the telescope's performance and design. A comparison with the Hydrogen Epoch of Reionization Array antenna is also shown demonstrating the potential use of the SKA1-LOW antenna for the delay-spectrum technique to detect the EoR.
External DOI: https://doi.org/10.1093/mnras/stx904
This record's URL: https://www.repository.cam.ac.uk/handle/1810/296334