AAVP meeting Cambridge December 2010 Technology Trade –offs: Mid band Array and Elements Prof. A....
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Transcript of AAVP meeting Cambridge December 2010 Technology Trade –offs: Mid band Array and Elements Prof. A....
AAVP meeting Cambridge December 2010
Technology Trade –offs: Mid band Array and Elements
Prof. A. K. Brown1
1 School of Electrical and Electronic Engineering
The University of Manchester, PO Box 88, Manchester, M13 9PL, U.K.
AA-mid
• 400MHz-1.4GHz• Wide angle , high sensitivity, multiple beam
forming: ~100’s square degrees• High survey speeds• High dynamic range capability• Polarimetry
Element size/type
Array Geometry
Antenna Array (Array Geometry ,element type)
Element Impendence , variation with frequency and scan Balanced/unbalanced feed
Low Noise Amplifier
Frequency sensitive weights“Calibratability”
Coupled noise (relates to geometry and LNA S11 LNA)
Beamformer design
Mutual Coupling
Sensitivityscan angle
Dynamic RangeSidelobe levelStability/calibration
(scan angle and sensitivity)
PolarimetryCalibration accuracyFrequency/angular
effect
Minimise Cost /Power
Minimise NInfrastructure costData transportThrough life costs: MTBF/MTCF/MTTRetc
Sidelobe level
Bandwidth
0.8 0.9 1 1.1 1.2 1.3 1.4100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
250
High frequency (GHz)
Ma
xim
um
ele
me
nt s
pa
cin
g (
mm
)
/(1+sinmax
),max
=30o
ORA element spacing/(1+sin
max),
max=45o
ORA element spacing
EMBRACE Antenna development
Mechanics evolved toward trustworthy and producible antenna element.
Printed Vivaldi
Planar structure
• The rings are attached to the surface of the expanded polystyrene foam (EPS) with a defined separation between two layers and the groundplane
• Polarimetry- frequency/scan angle dependance• LNA selection- noise, balance/unbalanced,
power requirements etc• Cost reduction/production
engineering/environmental analysis• Tie down the reliability analysis, LRU policy etc
• Come a long way during SKADS– Downselected to two basic types, one at a more
advanced stage of technological readiness, the other offering possibly further cost reductions and different detailed electro-magnetics
– Choice and design of LNA critical – eg shielding requirements, physical size etc
– 1st quarter next year technology review
• EMRACE development plus background research programme will prove a crucial tool
Thank you!
COBRA DANEMid1970’s
Dual Polarization Vivaldi
Good radiation
Anomaly