Transcript Slide 1
2-Polarisations 2-PAD All Digital Dr Georgina Harris / Prof Tony Brown SKADS System Design and Team Leader, University of Manchester Thanks to the 2-PAD Team: Manchester Chris Shenton, Tim Ikin, Aziz AhmedSaid, Richard Whitaker, Tony Brown, Dan Kettle, Mina Panahi Oxford Cambridge Astron Mike Jones, Kris Zarb Adami, Sasha Shidewy Andrew Faulkner Jan Geralt bij de Vaate, Raymond van den Brink 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 1 2-PAD Aims • To produce a flexible platform upon which to test a variety of subsystems for the Aperture Array for the SKA • Digital beamforming – Prove it can be done – Realistic technology projections for cost/ power – Low self induced RFI – Low cost interconnects are feasible • Dual polarisation measurements • Proof of calibration at tile level 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 2 2-PAD System Design Bunker RFI Shield Ant. polarisation Analogue Conditioning 64 dual channels 4 off Beamformer. Processors Total 128 inputs +ve Reg Signal Conditioning Rack Outdoors 4th SKADS Workshop, Lisbon, 2-3 October 2008 Output Beams Control Processor ....... Buffers Time standard Line Tx/Rx Up to ~20m Beam combiner Processor 64 elements x2 polarisations Digital Preprocessor From other beamformer proc. PSU Beamformer Processing ....... Analog Interconnect CAT7? ADC Analog Conditioning Digital Preprocessor ..... ..... PCB LNA ADC PSU Processor Control Processing Rack Bunker 2-PAD Georgina Harris 3 Antennas • 2-PAD will use 3 sets of array antennas • Each antenna tile will be 16 x 16 dual polarisation elements • The central 8 x 8 elements will be ‘active’, i.e. the signals from these antennas will be amplified and processed • The remaining antennas will be ‘loaded’ elements, i.e. they are present only to reduce the edge effects on the central 8 x 8 • Each antenna type is due to be produced as a passive tile for RF testing • After testing, the active antennas will be used for 2-PAD. 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 4 Antennas FlowPAD antenna • from our colleagues at Astron • used as a reference design by which to benchmark our other antennas 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 5 Antennas BECA • (Bunny Ear Combline Antenna) • Designed by the University of Manchester • A development of a Vivaldi Structure 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 6 Antennas ORA (Octagon Ring Antenna) • Designed by the University of Manchester • New Antenna Design – see talk by David Zhang 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 7 2-PAD LNA • The LNA for each antenna must be impedance matched and designed to integrate mechanically with the antenna • There are currently three teams working on LNAs in SKADS for 2-PAD – A completely new single-ended LNA developed in Indium Phosphide in Manchester – A differential LNA designed at ASTRON at 150W impedance for use with FlowPAD and BECA antennas – A differential LNA made up from discrete components in Manchester at 150W for use with FlowPAD and BECA antennas • It is likely that the discrete component LNA will be installed on 2-PAD initially, however, it will be possible for each LNA to undergo validation on the 2-PAD platform. 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 8 Gain Chain Version 1 Gain = 72dB Designed constructed and characterised by Richard Morrow 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 9 2-PAD System Design Bunker Analog RFI Shield Conditioning Ant. polarisation 64 dual channels 4 off Beamformer. Processors Total 128 inputs +ve Reg • Analogue signal conditioning Time on replaceable mezzanine Control standard Buffers Processor board • Off-the-shelf A/D initially Signal Conditioning•Rack Processing Rack and FPGA for data conversion initial signal processing 4th SKADS Workshop, Lisbon, 2-3 October 2008 Output Beams ....... Signal conditioning module Line Tx/Rx Outdoors Beam combiner Processor Up to ~20m Digital Preprocessor From other beamformer proc. 64 elements x2 polarisations PSU Beamformer Processing ....... Analog Twisted Pair ADC Analog Conditioning Digital Preprocessor ..... ..... PCB LNA ADC PSU Processor Control mini-Bunker 2-PAD Georgina Harris 10 Receivers Front-end Gain. Shielded Bunker Analogue Conditioner And Sampling Rack Processor Rack 20Gb Conditioning Acquisition Module &Processing Processor Blade Processor Blade Conditioning Acquisition Module &Processing Processor Blade Processor Blade Conditioning Acquisition Module &Processing Processor Blade Processor Blade Conditioning Acquisition Module &Processing Processor Blade Processor Blade 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 11 Signal conditioning Power Module 2-channel signal conditioning module Clock Module 2-channel acquisition and processing module 2 x 10Gb Links Signals from field 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 12 Analogue Conditioning Board Front Panel Diff. Pair Balun and DC Power Connector Filter TV Filter Lo By-pass Filter Hi Step attenuator Slope/ Gain Diff. Pair Power Reg Control Diff. Pair Power Reg Balun and DC Power Filter TV Filter Lo By-pass Filter Hi 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Step attenuator Slope/ Gain Diff. Pair Georgina Harris 13 Analogue Conditioning Board 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 14 DAQ Board Front Panel Connector Differential Pair Power Regs. Gain 4x PHY A to D Converter Differential Pair 10Gbps FPGA 10Gbps 4x PHY Gain Clock Dist. 4th SKADS Workshop, Lisbon, 2-3 October 2008 Management 2-PAD Georgina Harris 15 DAQ Board 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 16 2-PAD System Design Bunker Analog RFI Shield Conditioning Ant. polarisation 64 dual channels 4 off Beamformer. Processors Total 128 inputs +ve Reg Outdoors 4th SKADS Workshop, Lisbon, 2-3 October 2008 Output Beams Signal Conditioning • PrepSKA follow-on workRack to further investigate options Control Processor Line Tx/Rx • 2-PAD Designed to enable the Time standard testing of different Buffers types of processing Up to ~20m ....... Processing Subsystem Beam combiner Processor Digital Preprocessor From other beamformer proc. PSU Beamformer Processing ....... 64 elements x2 polarisations Analog Twisted Pair ADC Analog Conditioning Digital Preprocessor ..... ..... PCB LNA ADC PSU Processor Control Processing Rack mini-Bunker 2-PAD Georgina Harris 17 Initial Processing for 2-PAD Cyclops processor (IBM) • Cyclops blades in high-bandwidth rack • 80 GFlops/blade • Up to 48 blades/rack • SIMD Architecture • 160 thread units per chip Further Options – see Chris Shenton’s presentation 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 18 Cyclops frame at Jodrell 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 19 Cooling System • We have a cooling system for 2-PAD which includes: • A closed-loop controlled water cooling system used to cool the processor chips to keep them running at their most efficient • An air conditioning system used to cool the other electronics in the bunker • The two systems work together to keep the electronics at the correct temperature and humidity without compromising the RFI shielding of the bunker • This cooling system will make use of ‘free’ uncooled air from outside the bunker whenever ambient temperatures permit. 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 20 2-PAD System Design Bunker Analog RFI Shield Conditioning Ant. polarisation 64 dual channels 4 off Beamformer. Processors Total 128 inputs +ve Reg 4th SKADS Workshop, Lisbon, 2-3 October 2008 Output Beams Signal Conditioning Rack Outdoors ....... Buffers • RFI mitigation techniques • Housing and cooling system Time Control standard • ‘Standard’ container structure Processor Line Tx/Rx Up to ~20m Bunker and Shielding Beam combiner Processor 64 elements x2 polarisations Digital Preprocessor From other beamformer proc. PSU Beamformer Processing ....... Analog Twisted Pair ADC Analog Conditioning Digital Preprocessor ..... ..... PCB LNA ADC PSU Processor Control Processing Rack mini-Bunker 2-PAD Georgina Harris 21 Processing Bunker Design The processing bunker will be manufactured to the basic pattern of a standard transport container. Dual Function: 1. Provide RFI Shielding 2. Permits the processing bunker to be filled with computers before it is shipped 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 22 Bunker RFI shielding • • • • Connect via screened sockets Cables through tube Wrap foil along cable >60dB suppression at 1GHz, so far ARJ45 screened connectors 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 23 Potential SKA Station Layout 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 24 Software • A highly optimised kernel and software library has been created for the Cyclops processor from scratch in Manchester • A comprehensive MATLAB broadband beamforming model has been developed • We have a vendor developed software simulator for the Cyclops processor and the first version single polarisation beamformer has been implemented (in the simulator environment). This is currently being validated against the MATLAB model (refer to presentation by Aziz AhmedSaid). 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 25 2-PAD should be integrated and ready for test by Q1 2009! 4th SKADS Workshop, Lisbon, 2-3 October 2008 2-PAD Georgina Harris 26