Receiver architecture of the thousand-element array (THEA)

G.W. Kant, Andre B.J. Kokkeler, A.B. Smolders, A.W. Gunst

Research output: Contribution to conferencePaperAcademicpeer-review

7 Citations (Scopus)
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Abstract

As part of the development of a new international radio-telescope SKA (Square Kilometre Array), an outdoor phasedarray prototype, the THousand Element Array (THEA), is being developed at NFRA. THEA is a phased array with 1024 active elements distributed on a regular grid over a surface of approximately 16 m2. The array is organised into 16 units denoted as tiles. THEA operates in the frequency band from 750 to 1500 MHz. On a tile the signals from 64 antenna elements are converted into two independent RF beams. Two times 16 beams can be made simultaneously with full sensitivity by the real-time digital beam former of the THEA system. At the output of each tile the analog RF signal from a beam is converted into a 2 × 12-bit digital quadrature representation by a receiver system. A double super-heterodyne architecture is used to mix the signal band of interest to an intermediate frequency of 210 MHz. The IF-signal is shifted to baseband by means of a partly digitally implemented I/Q mixer scheme. After a quadrature mixer stage, the I and Q signals are digitised by means of 12 bit A/D converters at 40 MS/s. Implementing a part of the mixing scheme digitally offers the flexibility to use different I/Q architectures, e.g. Hartley and Weaver mixer setups. This way the effect of RFI in different mixing architectures can be analyzed. After the digital processing, the samples are multiplexed, serialised and transported over fibres to the central adaptive digital beam former unit where the signals from all tiles are combined giving 32 beams. This paper focuses on the design choices and the final implementation of the THEA system. In particular, the receiver architecture is addressed. A digital solution is presented, which enables switching between a Hartley and a Weaver based mixer scheme.
Original languageEnglish
Pages287-298
Number of pages12
DOIs
Publication statusPublished - 2000
EventSPIE Astronomical Telescopes + Instrumentation 2000 - Munich, Germany
Duration: 27 Mar 20001 Apr 2000

Conference

ConferenceSPIE Astronomical Telescopes + Instrumentation 2000
CountryGermany
CityMunich
Period27/03/001/04/00

Fingerprint

Tile
Radio telescopes
Digital signal processing
Frequency bands
Antennas
Fibers

Keywords

  • EWI-17521
  • IR-70140

Cite this

Kant, G. W., Kokkeler, A. B. J., Smolders, A. B., & Gunst, A. W. (2000). Receiver architecture of the thousand-element array (THEA). 287-298. Paper presented at SPIE Astronomical Telescopes + Instrumentation 2000, Munich, Germany. https://doi.org/10.1117/12.390423
Kant, G.W. ; Kokkeler, Andre B.J. ; Smolders, A.B. ; Gunst, A.W. / Receiver architecture of the thousand-element array (THEA). Paper presented at SPIE Astronomical Telescopes + Instrumentation 2000, Munich, Germany.12 p.
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author = "G.W. Kant and Kokkeler, {Andre B.J.} and A.B. Smolders and A.W. Gunst",
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Kant, GW, Kokkeler, ABJ, Smolders, AB & Gunst, AW 2000, 'Receiver architecture of the thousand-element array (THEA)' Paper presented at SPIE Astronomical Telescopes + Instrumentation 2000, Munich, Germany, 27/03/00 - 1/04/00, pp. 287-298. https://doi.org/10.1117/12.390423

Receiver architecture of the thousand-element array (THEA). / Kant, G.W.; Kokkeler, Andre B.J.; Smolders, A.B.; Gunst, A.W.

2000. 287-298 Paper presented at SPIE Astronomical Telescopes + Instrumentation 2000, Munich, Germany.

Research output: Contribution to conferencePaperAcademicpeer-review

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T1 - Receiver architecture of the thousand-element array (THEA)

AU - Kant, G.W.

AU - Kokkeler, Andre B.J.

AU - Smolders, A.B.

AU - Gunst, A.W.

PY - 2000

Y1 - 2000

N2 - As part of the development of a new international radio-telescope SKA (Square Kilometre Array), an outdoor phasedarray prototype, the THousand Element Array (THEA), is being developed at NFRA. THEA is a phased array with 1024 active elements distributed on a regular grid over a surface of approximately 16 m2. The array is organised into 16 units denoted as tiles. THEA operates in the frequency band from 750 to 1500 MHz. On a tile the signals from 64 antenna elements are converted into two independent RF beams. Two times 16 beams can be made simultaneously with full sensitivity by the real-time digital beam former of the THEA system. At the output of each tile the analog RF signal from a beam is converted into a 2 × 12-bit digital quadrature representation by a receiver system. A double super-heterodyne architecture is used to mix the signal band of interest to an intermediate frequency of 210 MHz. The IF-signal is shifted to baseband by means of a partly digitally implemented I/Q mixer scheme. After a quadrature mixer stage, the I and Q signals are digitised by means of 12 bit A/D converters at 40 MS/s. Implementing a part of the mixing scheme digitally offers the flexibility to use different I/Q architectures, e.g. Hartley and Weaver mixer setups. This way the effect of RFI in different mixing architectures can be analyzed. After the digital processing, the samples are multiplexed, serialised and transported over fibres to the central adaptive digital beam former unit where the signals from all tiles are combined giving 32 beams. This paper focuses on the design choices and the final implementation of the THEA system. In particular, the receiver architecture is addressed. A digital solution is presented, which enables switching between a Hartley and a Weaver based mixer scheme.

AB - As part of the development of a new international radio-telescope SKA (Square Kilometre Array), an outdoor phasedarray prototype, the THousand Element Array (THEA), is being developed at NFRA. THEA is a phased array with 1024 active elements distributed on a regular grid over a surface of approximately 16 m2. The array is organised into 16 units denoted as tiles. THEA operates in the frequency band from 750 to 1500 MHz. On a tile the signals from 64 antenna elements are converted into two independent RF beams. Two times 16 beams can be made simultaneously with full sensitivity by the real-time digital beam former of the THEA system. At the output of each tile the analog RF signal from a beam is converted into a 2 × 12-bit digital quadrature representation by a receiver system. A double super-heterodyne architecture is used to mix the signal band of interest to an intermediate frequency of 210 MHz. The IF-signal is shifted to baseband by means of a partly digitally implemented I/Q mixer scheme. After a quadrature mixer stage, the I and Q signals are digitised by means of 12 bit A/D converters at 40 MS/s. Implementing a part of the mixing scheme digitally offers the flexibility to use different I/Q architectures, e.g. Hartley and Weaver mixer setups. This way the effect of RFI in different mixing architectures can be analyzed. After the digital processing, the samples are multiplexed, serialised and transported over fibres to the central adaptive digital beam former unit where the signals from all tiles are combined giving 32 beams. This paper focuses on the design choices and the final implementation of the THEA system. In particular, the receiver architecture is addressed. A digital solution is presented, which enables switching between a Hartley and a Weaver based mixer scheme.

KW - EWI-17521

KW - IR-70140

U2 - 10.1117/12.390423

DO - 10.1117/12.390423

M3 - Paper

SP - 287

EP - 298

ER -

Kant GW, Kokkeler ABJ, Smolders AB, Gunst AW. Receiver architecture of the thousand-element array (THEA). 2000. Paper presented at SPIE Astronomical Telescopes + Instrumentation 2000, Munich, Germany. https://doi.org/10.1117/12.390423