Square kilometre array station configuration using two-stage beamforming
The lowest frequency band (70–450 MHz) of the Square Kilometre Array (SKA) will consist of sparse aperture arrays grouped into geographically localised patches or stations. Signals from thousands of antennas in each station will be beamformed to produce station beams which form the inputs for the ce...
| Main Authors: | , , , , , |
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| Format: | Journal Article |
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CSIRO
2013
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| Online Access: | http://hdl.handle.net/20.500.11937/14224 |
| _version_ | 1848748565734621184 |
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| author | Jiwani, Aziz Colegate, Timothy Razavi-Ghods, N. Hall, Peter Padhi, Shantanu Bij de Vaate, J. |
| author_facet | Jiwani, Aziz Colegate, Timothy Razavi-Ghods, N. Hall, Peter Padhi, Shantanu Bij de Vaate, J. |
| author_sort | Jiwani, Aziz |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | The lowest frequency band (70–450 MHz) of the Square Kilometre Array (SKA) will consist of sparse aperture arrays grouped into geographically localised patches or stations. Signals from thousands of antennas in each station will be beamformed to produce station beams which form the inputs for the central correlator. Two-stage beamforming within stations can reduce SKA-low signal processing load and costs, but has not been previously explored for the irregular station layouts now favoured in radio astronomy arrays. This paper illustrates the effects of two-stage beamforming on sidelobes and effective area, for two representative station layouts (regular and irregular gridded tiles on an irregular station). The performance is compared with a single-stage, irregular station. The inner sidelobe levels do not change significantly between layouts, but the more distant sidelobes are affected by the tile layouts; regular tile creates diffuse, but regular, grating lobes. With very sparse arrays, the station effective area is similar between layouts. At lower frequencies, the regular tile significantly reduces effective area, hence sensitivity. The effective area is highest for a two-stage irregular station, but it requires a larger station extent than the other two layouts. Although there are cost benefits for stations with two-stage beamforming, we conclude that more accurate station modelling and SKA-low configuration specifications are required before design finalisation. |
| first_indexed | 2025-11-14T07:07:04Z |
| format | Journal Article |
| id | curtin-20.500.11937-14224 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:07:04Z |
| publishDate | 2013 |
| publisher | CSIRO |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-142242017-09-13T14:06:27Z Square kilometre array station configuration using two-stage beamforming Jiwani, Aziz Colegate, Timothy Razavi-Ghods, N. Hall, Peter Padhi, Shantanu Bij de Vaate, J. instrumentation: interferometers telescopes techniques: interferometric The lowest frequency band (70–450 MHz) of the Square Kilometre Array (SKA) will consist of sparse aperture arrays grouped into geographically localised patches or stations. Signals from thousands of antennas in each station will be beamformed to produce station beams which form the inputs for the central correlator. Two-stage beamforming within stations can reduce SKA-low signal processing load and costs, but has not been previously explored for the irregular station layouts now favoured in radio astronomy arrays. This paper illustrates the effects of two-stage beamforming on sidelobes and effective area, for two representative station layouts (regular and irregular gridded tiles on an irregular station). The performance is compared with a single-stage, irregular station. The inner sidelobe levels do not change significantly between layouts, but the more distant sidelobes are affected by the tile layouts; regular tile creates diffuse, but regular, grating lobes. With very sparse arrays, the station effective area is similar between layouts. At lower frequencies, the regular tile significantly reduces effective area, hence sensitivity. The effective area is highest for a two-stage irregular station, but it requires a larger station extent than the other two layouts. Although there are cost benefits for stations with two-stage beamforming, we conclude that more accurate station modelling and SKA-low configuration specifications are required before design finalisation. 2013 Journal Article http://hdl.handle.net/20.500.11937/14224 10.1017/pas.2012.023 CSIRO fulltext |
| spellingShingle | instrumentation: interferometers telescopes techniques: interferometric Jiwani, Aziz Colegate, Timothy Razavi-Ghods, N. Hall, Peter Padhi, Shantanu Bij de Vaate, J. Square kilometre array station configuration using two-stage beamforming |
| title | Square kilometre array station configuration using two-stage beamforming |
| title_full | Square kilometre array station configuration using two-stage beamforming |
| title_fullStr | Square kilometre array station configuration using two-stage beamforming |
| title_full_unstemmed | Square kilometre array station configuration using two-stage beamforming |
| title_short | Square kilometre array station configuration using two-stage beamforming |
| title_sort | square kilometre array station configuration using two-stage beamforming |
| topic | instrumentation: interferometers telescopes techniques: interferometric |
| url | http://hdl.handle.net/20.500.11937/14224 |