Transcript Project Management Structure

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.
AAVP meeting Cambridge December 2010
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
Antenna Array (Array
Geometry ,element type)
Mutual Coupling
Array Geometry
Low Noise Amplifier
Element Impendence ,
variation with frequency and
scan
Balanced/unbalanced feed
Coupled noise (relates to
geometry and LNA S11 LNA)
Beamformer design
Frequency sensitive weights
“Calibratability”
Bandwidth
Sensitivity
scan angle
Dynamic Range
Sidelobe level
Stability/calibration
(scan angle and sensitivity)
Polarimetry
Calibration accuracy
Frequency/angular effect
Minimise
Cost /Power
Minimise N
Infrastructure cost
Data transport
Through life costs:
MTBF/MTCF/MTTR
etc
Maximum element spacing (mm)
250
240
/(1+sinmax),max=30o
230
ORA element spacing
220
/(1+sin
210
ORA element spacing
o
),

=45
max max
200
190
180
170
160
150
140
130
120
110
100
0.8
0.9
1
1.1
1.2
High frequency (GHz)
1.3
1.4
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 DANE
Mid1970’s
Dual Polarization Vivaldi
Good radiation
Anomaly