Evolution of the 2-PAD Front-End
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Sascha Schediwy [email protected] Evolution of the 2-PAD Evolution of the 2-PAD Front-End Front-End 3 rd SKADS Workshop – April 2008 Andy Faulkner Aziz Ahmedsaid Chris Shenton Mike Jones Peter Hastings Sascha Schediwy Georgina Harris Richard Morrow Tim Ikin Oxford Astrophysics Jodrell Bank Observatory Hamid Dabiri Khah Kris Zarb-Adami Mark Jones 2-PAD: Dual-Polarisation All Digital Aperture Array (DS4T6)
description
Oxford Astrophysics. Jodrell Bank Observatory. Hamid Dabiri Khah Kris Zarb-Adami Mark Jones. Mike Jones Peter Hastings Sascha Schediwy. Andy Faulkner Aziz Ahmedsaid Chris Shenton. Georgina Harris Richard Morrow Tim Ikin. Evolution of the 2-PAD Front-End. - PowerPoint PPT Presentation
Transcript of Evolution of the 2-PAD Front-End
Sascha Schediwy [email protected]
Evolution of the 2-PAD Front-EndEvolution of the 2-PAD Front-End
3rd SKADS Workshop – April 2008
Andy Faulkner Aziz Ahmedsaid Chris Shenton
Mike Jones Peter Hastings Sascha Schediwy
Georgina Harris Richard Morrow Tim Ikin
Oxford Astrophysics Jodrell Bank Observatory
Hamid Dabiri Khah Kris Zarb-Adami Mark Jones
2-PAD: Dual-Polarisation All Digital Aperture Array (DS4T6)
Sascha Schediwy [email protected]
2-PAD Analogue Signal Path2-PAD Analogue Signal Path
+ve Reg
Ant.polarisation
LNA Custom Analog Chip(s)
PCB
Analog Twisted
Pair
BunkerRFI Shield
PCBPlug
PSU
Custom Analog Chip
4 i/ps each
4-b
it AD
C
...
...
Beam
former
Processor
.......Total 512 inputs
256 elements x2 polarisations
Beam
combing
Processor
.......
Station processors
HSS interface
Custom Digital Chip
PSU
4 i/ps each
4-b
it AD
C
4 off BeamformerProcessors Processor
ControlProcessor
Lin
eT
x/Rx
Station Control
Timestandard
Buffers
Fro
m o
the
r b
ea
mfo
rme
r pro
c.
Noise sourceSwitch
128 analog i/psDigital beams out
Analog sig. conditioning control
3rd SKADS Workshop – April 2008
Sascha Schediwy [email protected]
2-PAD Front-End Module2-PAD Front-End Module
Line DriverLNA Amplification
Noise Diode
Power Regulator
MMICLNA
ReceiverBoard
3rd SKADS Workshop – April 2008
Front-End Module
CoaxialCable
TwisterPair
Shielded Bunker Wall
Antenna
Eventual Goal
Sascha Schediwy [email protected]
Previous Front-End PrototypesPrevious Front-End Prototypes
Version Input Output Voltage Power Gain
Gain Chain v1: single differential 5V 150mA8.5V 320mA
3.47 W 80 dB
Gain Chain v2: single single 5V 150mA8.5V 160mA
2.11 W 80 dB
Gain Chain v3: single single 5V 150mA8.5V 60mA12V 525mA
7.56 W 68 dB
3rd SKADS Workshop – April 2008
Gain Chain v1 Gain Chain v2 Gain Chain v3
Several Issues Identified!
Sascha Schediwy [email protected]
Next Generation Front-EndNext Generation Front-End
3rd SKADS Workshop – April 2008
Still More Outstanding Issues!
Address identified issues, plus: Dual-polarisation front-end module Mass production plastic enclosure Cheap metallisation of surfaces Temperature stabilisation/cooling
Sascha Schediwy [email protected]
Antenna Specific LNAsAntenna Specific LNAs
Embrace Tile
Flowpad
Oxford Log-Period Dipole
3rd SKADS Workshop – April 2008
Sascha Schediwy [email protected]
Output – Twisted Pair CableOutput – Twisted Pair Cable
3rd SKADS Workshop – April 2008
Coaxial cable problematic Results in very high connector densities Expensive
Twisted pair (CAT7) Cheaper and more channels per area Requires differential output
Sascha Schediwy [email protected]
Current Front-End VersionCurrent Front-End Version
Balun TERACoax /
Semi Rigid (~1m)
CAT7(~20m)LNA
Amp1 Amp2 Amp3
Antenna Specific LNA Quad Channel Amplifier Box
SMASMA Amp?SMA
3rd SKADS Workshop – April 2008
Sascha Schediwy [email protected]
Conclusion and Further WorkConclusion and Further Work
First revision of current version nearing completion
We will continue to evolve the 2-PAD front-end until it reaches the functionality appropriate for the SKA
3rd SKADS Workshop – April 2008
Sascha Schediwy [email protected]
Gain Chain Versions 1 to 3Gain Chain Versions 1 to 3
Section Amplifier Gain 1dB Comp. NF VoltageAmp1 HMC374E 15 dB 22 dBm 1.5 dB 5.0V
Amp2 GALI-52 21 dB 15.5 dBm 2.7 dB 5.0V
Amp3 ERA-50SM 20 dB 17.5 dBm 3.3 dB 8.5V
Amp4 (GC1) MERA-7456 24 dB 18.5 dBm 2.7 dB 8.5V
Amp4 (GC2) GALI-84 24 dB 21.5 dBm 4.3 dB 8.5V
Amp4 (GC3) HELA-10 12 dB 30 dBm 3.5 dB 12V
Version Input Output Voltage Power GainGain Chain v1: single differential 5V 150mA
8.5V 320mA3.47 W 80 dB
Gain Chain v2: single single 5V 150mA8.5V 160mA
2.11 W 80 dB
Gain Chain v3: single single 5V 150mA8.5V 60mA12V 525mA
7.56 W 68 dB
3rd SKADS Workshop – April 2008
Sascha Schediwy [email protected]
Gain Chain Version 4 DesignGain Chain Version 4 Design
Commercial Front-end Module http://www.nuwaves-ltd.com/pdf/uHILNA%20Data%20Sheet.pdf
3rd SKADS Workshop – April 2008
Sascha Schediwy [email protected]
Oxford Log-Periodic DipoleOxford Log-Periodic Dipole
Physical Properties beam width: 22° (HPHW) forward gain: 11.5dBi low horizon side lobes frequency range: 0.3-1.0GHz return loss: better than −15dB
3rd SKADS Workshop – April 2008
Sascha Schediwy [email protected]
Oxford Log-Periodic DipoleOxford Log-Periodic Dipole
Physical Properties beam width: 22° (HPHW) forward gain: 11.5dBi low horizon side lobes frequency range: 0.3-1.0GHz return loss: better than −15dB
simulation limitation
cross-polarisation
forward gain
3rd SKADS Workshop – April 2008
Sascha Schediwy [email protected]
Complete Test ChainComplete Test Chain
SignalConditioning
Module
Amplifier Box
Commercial LNA (for testing this antenna only)
3rd SKADS Workshop – April 2008
