Transcript SKADS-LOGO - Square Kilometre Array Design Studies

Wideband Integrated Antennas
DS4-T4
Jan Geralt Bij de Vaate
ASTRON
DS4-T4
Jan Geralt Bij de Vaate
Wideband Integrated Antennas
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Task objectives:
– To design a tile of wide-band, low-cost, antenna elements
appropriate for dual-polarized, close-packed phased arrays and
to optimize their RF performance
DS4-T4
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Model and characterise antenna elements
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Develop cost effective solutions for integrating active receiver
components with the antenna
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To characterise the integrated antenna
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Develop photonic analogue data link
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To realize very low cost solutions for the radiator
SKADS Review 2006
Jan Geralt Bij de Vaate
Targets
• Tsys=
35K (excluding sky noise)
• Bandwidth > 3:1
• ‘full’ scan range etc. etc.....
• Tile cost target: to be defined but..
• 200 euros / m2
• Depending on:
– Location receivers (remote/integrated)
– Frequency band
– Number beams
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SKADS Review 2006
Jan Geralt Bij de Vaate
Partners
• ASTRON
• UMAN
• Oxford/UCAM
• FG-IGN
– CSIRO
– NRC
– OPAR
– INAF
– OMMIC
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SKADS Review 2006
Jan Geralt Bij de Vaate
Progress FG-IGN
• Evaluation of potential antenna elements
• Design of Vivaldi
• Design wideband dipole
• Design of wideband balun
• Far field Test range available
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SKADS Review 2006
Jan Geralt Bij de Vaate
Progress UK
• Development of specification 2-PAD
• Contribution to 2-PAD system design concept
• Initial array geometry studies
– Band Interleaving approach promising
• Element study and initial simulations
– Multi-choke exponential slot antenna
– Anti-podal slot element
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SKADS Review 2006
Jan Geralt Bij de Vaate
Progress CSIRO
• Work on linear connected arrays
• Target: 5 by 5 array for Focal Plane Array purpose
Progress NRC
• Focal Plane Array Vivaldi design
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SKADS Review 2006
Jan Geralt Bij de Vaate
Progress ASTRON
Antenna design tooling
• The Efficient finite array solvers are needed for SKA:
– The Characteristic Basis Function Method (CBFM)
enhances the MoM to solve electrically large problems
efficiently without comprising the accuracy
• Parallel Time Domain (FDTD) code on the LOFAR
BlueGene/L computer
– Together with prof. Mittra, PennState Univ.
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SKADS Review 2006
Jan Geralt Bij de Vaate
Active antenna design
• OMMIC: samples provided for differential LNA-antenna
• LNA ICs developed: focus on differential design
– Hot/cold test with diff load: 60K (should be 35K)
• Differential antenna
– Hot cold antenna tests still too high
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SKADS Review 2006
Jan Geralt Bij de Vaate
Localized vacuum LNA cooling
• 0.15 Watt cooling power for
20% TLNA reduction (ΔT 35
degrees
• 0.8 Watt cooling power: ΔT
50 degrees
• F Schreuder, J G Bij de Vaate, “Localized LNA cooling in
vacuum”, Therminic, Nice, France, September 2006
• G Jones, S Weinreb, “Thermoelectric cooling of LNAs to
200K”, URSI 2005
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SKADS Review 2006
Jan Geralt Bij de Vaate
Low cost radiator
• Low cost radiator
– Aluminum sheets
– Polyester with cupper stamped or
laser cut: 3€ / element
• Etching/Photolitho processes
should be avoided
• Inkjet printing / MID (molded interconnect
devices) Not feasible
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SKADS Review 2006
Jan Geralt Bij de Vaate
Schedule and milestones
• No changes:
• Next meeting: 14th September 2006, Manchester
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SKADS Review 2006
Jan Geralt Bij de Vaate
Conclusion
• Already good progress on all objectives
• First dual polarization antenna array build
• SKA readiness tile on schedule: low cost high
performance (EMBRACE compatible) tile
DS4-T4
SKADS Review 2006
Jan Geralt Bij de Vaate