SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Front-End Design for Mid-Frequency Aperture Array
David Zhang, A. K. Brown, Ming YangThe University of [email protected]
Severin Barth, S. Bosse, S. R. HarisonObs. de Paris, Nancay
Rui CaoKLAASA, CETC-38Pieter Benthem, David PrinslooASTRON, the Netherlands
E. de Lera-AcedoUniversity of Cambridge
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Outline• Full Differential Front-End Development
– Review of C-ORA (Crossed Octagonal Ring Antenna)– Prototype investigation– Active C-ORA array measurements– System integration with time delay based beamformer
• Single-Ended Front-End Development– ASTRON
• Active Vivaldi Antenna Array• Integration with phase shifter based beamformer
– KLAASA• Front-End solution and back-end processing
• Sparse Array Design for MFAA
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Review of Crossed Octagonal Ring Antenna (C-ORA) Design
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
C-ORA Design
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
The Layered Structure
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Metamaterial performance in C-ORA
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Prototyping and Active ORA Array Measurements
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
The 1 m2 ORA prototype facts
10x10 elements(1.25m x 1.25m) Dual-polarised for each element Frequency 400MHz to 1450MHz Element separation: 125mm Low profile (array thickness
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Gain measurements at field
0.5 1 1.50
5
10
15
20
25
30
35
40
45
50
Frequency(GHz)
Gai
n(dB
)
Simulated Gain 1x1 ORA without LNASimulated Gain 4x4 ORA without LNASimulated Gain 8x8 ORA without LNAMeasured Gain 4x4 with LNASimulated Gain 4x4 ORA + Measured Gain of LNA
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Gain comparison for 4x4 Arrays
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Raw cross polarisation – XPD
900MHz 1200MHz
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Calibration Error and IXR
𝑓𝑓𝑝𝑝𝑓𝑓𝑞𝑞
=𝐽𝐽𝑝𝑝𝑝𝑝 𝐽𝐽𝑝𝑝𝑝𝑝𝐽𝐽𝑞𝑞𝑝𝑝 𝐽𝐽𝑞𝑞𝑝𝑝
𝑒𝑒𝑝𝑝𝑒𝑒𝑝𝑝
𝑓𝑓 = 𝐽𝐽𝑒𝑒
𝑒𝑒 = 𝐽𝐽−1𝑓𝑓𝑓𝑓 + ∆𝑓𝑓 = (𝐽𝐽 + ∆𝐽𝐽) 𝑒𝑒 + ∆𝑒𝑒
∆𝑒𝑒𝑒𝑒
≤ 1 +2𝐼𝐼𝐼𝐼𝐼𝐼
∆𝑓𝑓𝑓𝑓
+∆𝐽𝐽𝐽𝐽
Raw voltageMeasured
voltage
An IXR of 25 dB limits the potential increasein the relative Stokes error during reconstruction to 22%
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
900MHz 1200MHz
The IXR (Intrinsic Cross-Polarisation)
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
The radiation pattern measurement
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
-50
-40
-30
-20
-10
0
10
20
-70
-65
-60
-55
-50
-45
-40
-35
-30
-25
-20
-15
-10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70
900MHz,4x4 beamformed, D-Plane
Co-Pol X-Pol
-35-30-25-20-15-10-505
10
-70
-65
-60
-55
-50
-45
-40
-35
-30
-25
-20
-15
-10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70
1400MHz, 4x4 beamformed, D-plane
Co-Pol X-Pol
The 4x4 beamformed patterns, measured
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Measured immersed element patterns
900MHz, E-plane 1400MHz, E-plane
900MHz, H-plane 1400MHz, H-plane
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
The System Integration With Time Delay based beamformer
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAYBeamformer board
ORA filtering board
Quad board
X-pol antenna inputs Y-pol antenna inputs
Beam A output
Beam B output
Time delay based beamformer solution for dual polarisation with two beams
Beam A output
Beam B output
All boards are developed at Nançay
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Beamformer Chip Performance
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Front-End R&Dat
Station de Radioastronomie de NançayObservatoire de Paris
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Adjustable time delayASIC 4 channelsTime delay = 1,2ns * 2 = 2,4 nsStep = 20 ps * 2Error pĥase = ±10 degreesFreq bandwidth = [400-1500 MHz]
4 TD / QuadBoard→ 8 TD for 2 m2
Quad Board
X-pol, Beam A&B
Y-pol, Beam A&B
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
NEW LNA Topology
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Single-Ended Front-End DevelopmentASTRON
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Vivaldi Tile for MFAA
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Active array with low noise solution
LNAs are integrated at the feeding points, SATA interface to the beamformer board
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Dual polarisation two beams beamformer
8 elements beamformer PCB for dual polarisations2 beams for X polarisations2 beams for Y polarisations
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Single-Ended Front-End DevelopmentKLAASA
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Architecture
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
4x4 to 1 analogue beam configuration
• 4x4 output 1 analogue beam• 16x16x2 tile will generate 32
beams• 1 CTPM can process 512
antenna elements
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
4x4 to 16 analogue beams configuration
• 4x4 output 16 analogue beam• 16x16x2 tile will generate 512
beams• 16 CTPM can process 512
analogue beams
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
CTPM with three layered structure
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Prototyping
32 channels with optical receivers
32 AD channels Processing
KLAASA has completed the test of V1.0For LFAA
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
CTPM for MFAA
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Log-Periodic Dipole Antenna for SKA-AAMid(Sparse Array)
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Log-Periodic Dipole Antenna for MFAA
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
LPDA for MFAA and LNA
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Tile demonstrator at Lord’s Bridge
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAY
Summary
• Different front-end technologies become more mature• Dual polarisation with dual beams per polaristation can
be realised with phase shift or time delay based analogue beamforming
• High polarimetry performance can be achieved• Irregular distribution of elements in the array, random
thinning techniques can be explored to further reduce the total number of elements
SKA AIP Meeting, ASTRON, 8-9 June, 2017
MID-FREQUENCY APERTURE ARRAYThank you
Front-End Design for Mid-Frequency Aperture ArrayOutlineReview of Crossed Octagonal Ring Antenna (C-ORA) DesignC-ORA DesignThe Layered StructureMetamaterial performance in C-ORAPrototyping and Active ORA Array MeasurementsThe 1 m2 ORA prototype factsGain measurements at fieldSlide Number 10Slide Number 11Calibration Error and IXRSlide Number 13Slide Number 14Slide Number 15Slide Number 16The System Integration With Time Delay based beamformerSlide Number 18Beamformer Chip PerformanceFront-End R&D�at �Station de Radioastronomie de Nançay�Observatoire de ParisSlide Number 21Slide Number 22Slide Number 23Slide Number 24Slide Number 25Single-Ended Front-End Development�ASTRONVivaldi Tile for MFAAActive array with low noise solutionDual polarisation two beams beamformerSingle-Ended Front-End Development�KLAASAArchitecture4x4 to 1 analogue beam configuration4x4 to 16 analogue beams configurationCTPM with three layered structurePrototypingCTPM for MFAASlide Number 37Log-Periodic Dipole Antenna for MFAALPDA for MFAA and LNATile demonstrator at Lord’s BridgeSummarySlide Number 42