An Introduction to Multi-Function Phased Array Radars

1. MULTI-FUNCTION PHASED ARRAY RADAR
SatyanarayanaS

2. AGENDA
•
Evolution of RADAR Technology
•
Issues and Challenges
•
Phased Array RADARS
•
Components of a Phased Array RADAR
•
Future Technologies

3. CONVENTIONAL RADAR
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•
Centralized Transmitter
•
Produce beam pattern by reflector
•
Scanning achieved by physically moving the antenna
•
Surveillance and tracking method
–
Surveillance: Fan-based beam
–
Tracking: Pencil beam
DISPLAY
TARGET
Transmit and Receive beam feed
ROTATING JOINT
TRANSMITTER
DUPLEX
RECEIVER
PROCESSOR
Data to System
DISH
Continuous Rotation
SINGLE FUNCTION RADARS

4. PASSIVE PHASED ARRAY RADAR
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•
Beam shaping without mechanical movement
–
Phase shifters, Attenuators and Switching elements
HIGH-POWER VARIABLE PHASE SHIFTERS AND ATTENUATORS
DISPLAY
TARGET
Planar Array (Example of 9 radiators, but usually 1000+)
Distribution
TRANSMITTER
DUPLEX
RECEIVER
PROCESSOR
Data to System
Operator / System Requirement
D1
D2
D3
D4
D5
D6
D7
D8
D9
Computer Beam Control
Control

5. ISSUES & CHALLENGES
•
ISSUES
–
80% of the effective RF power is lost
–
95% of prime power is lost
–
20% of RF power is used for detection
•
CHALLENGES
–
Intense jamming
–
Severe clutter
–
Very low RADAR cross section
–
Rapid reaction/updates
–
Multiple Targets
–
Mobility/Transportability
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6. ACTIVE PHASED ARRAY RADAR
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•
T/R module behind each radiating element
•
Transmitter power distributed through many Power Amplifiers (HPA)
•
Small signal loss between HPA and LNA (Low-noise Amplifier)
PASSIVE ANTENNA CONNECTS TO HPA & LNA
HPA
LNA
HPA
LNA
TRM1
TARGET
Planar Array
Phase and Amp Control
Beam Steering Computer
Exciter
TRMn
Down Converter
Transmit / Receive Losses
Signal Processing

7. ADVANTAGES
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•
Waveguide can be replaced with low-loss cables
•
No tube warm-up time
•
Replace tube technologies with solid-state technology
•
Improved detection sensitivity by improving noise figure
•
MTBF better for solid-state electronics than tubes
•
Graceful degradation performance with component failures
•
Improved detection sensitivity in the presence of clutter
•
Prime power requirements are also greatly reduced
ACTIVE SYSTEMS WITH HIGH DUTY CYCLE / LOW PEAK POWER

8. EVOLUTION
During 1960 –1970
New technologies developed for Space and Military applications
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For Commercial applications
Military & Space applications
During 2010 –2020
New technologies developed for commercial applications such as wireless / base station

9. T/R MODULES
•
Receive Path: High Power Switch, Low Noise Amplifier & Band Pass filters
•
Common Arm: Digital Phase Shifter, Digital Attenuator
•
Transmit Path: Driver Amplifier and Power Amplifier
•
DC Power Conditioning: EMI Filter, Buck converters and LDOs
•
Digital Controls: Phase Shifters, Attenuators, Switches
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Switch
High Power Switch
Power Amplifier
Switch
Low Noise Amplifier
Transmitter Path
Receiver Path
Controls
DC Power Conditioning
Switch
50 V
Common Arm
EFFICIENT AND LOW NOISE

10. ADVANCEMENTS
•
GaNDevices
–
High efficiency (PAE)
–
Higher gain per stage
–
Easier Impedance matching
–
Wider Bandwidth
–
High power SPDT
–
Low noise Amplifiers
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COMPLETE SOLID-STATE

11. SUB-ARRAY CONCEPT
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DIGITAL AT SUB ARRAY LEVEL
Sub array T/R Modules
Beam steering
(Phase & Amplitude)
On-array Components
Receiver (1 … N) Down Converter ADC
Digital Beam former
Exciter
Digital Signal processor
Sum Beam
Difference Beam
Control Computer

12. FUTURE ACTIVE ANTENNA
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T/R Modules
Beam steering (Phase and Amplitude)
On-array Components
Transceiver
1 … M per element
Digital Beam former
Digital Signal processor
Control Computer
DIGITAL AT ELEMENT LEVEL

13. BENEFITS OF DIGITAL BEAM FORMING
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INCREASE IN DYNAMIC RANGE DUE TO DISTRIBUTED ADCs
HPA
LNA
HPA
LNA
HPA
LNA
HPA
LNA
RECEIVER
RECEIVER
RECEIVER
RECEIVER
ADC
ADC
ADC
ADC
Digital Beam Forming
Sum Beam
X1
X2
Xn
….
Beam forming on Digital data
•
System Dynamic Range is n times the ADC Dynamic Range
HPA
LNA
HPA
LNA
HPA
LNA
HPA
LNA
Beam Forming
Sum Beam
X1
X2
Xn
….
Beam forming on Analog (RF) signals
RECEIVER
ADC
•
System Dynamic Range is limited by ADC Dynamic Range

14. MULTI FUNCTIONS
•
Enables MPAR to rapidly and adaptively survey the atmosphere, while serving aviation needs
•
Simultaneous tracking on multiple targets coming from many directions
•
Enables multiple beams at different frequencies in the band, simultaneously
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4 Active antenna Fixed Faces (top view)
Mission A
Mission B
Mission C
Face 1
Face 3
Face 2
Face 4
Mission D
Δf1
Δf2
Δf3
Δf4
f1
f2
f3
f4
x MHz
y MHz

15. COST OPTIMIZATION
•
Scalable Array size
–
Enables same array hardware for multiple aperture configurations
•
Tile architecture
–
Reduce interconnections, simplify assembly and test processes
•
Low-peak Power
–
Allows standard surface mount packages
•
Exploit Wireless Industry Technology
–
Leverages commercial manufacturing and test processes
•
Replace existing RADARs that are used for weather and aircraft surveillance with MPAR
–
Reduced maintenance and improved availability [Higher power transmitter and mechanism for pointing the antenna]
–
Savings in uniform maintenance can be very substantial
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16. PHASED ARRAY RADAR ARCHITECTURE
•
Difference in the construction of
–
Transmitter
–
Antenna
–
Receiver Chain
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ModulesArray
RADAR Manager
Digital Beam Forming
Array
Rx * s
Transmit Signal Generation
Power and Cooling
Signal Processing
Tracking Filters
To Weapon Systems

17. SMALL RADAR TECHNOLOGY
•
Placement of short-range RADARS about 30kms apart arranged in a network
•
Achieves improved weather surveillance compared to todays long range RADAR technologies
•
Can be installed next to existing towers and roof tops
•
Long-range RADARS fundamentally incapable of providing comprehensive low-level coverage owing to the curvature of the earth
•
Short range RADARS require less than 100 watt of average transmit power
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Image Courtsey: AFFORDABLE PHASED ARRAY WEATHER RADARS: STARTING TO BECOME A REALITY, by Prof. David J. McLaughlin, Engineering Research Center for Collaborative Adaptive Sensing of the Atmosphere (CASA), Department of Electrical and Computer Engineering, College of Engineering, University of Massachusetts

18. ARRAY SPECIFICATION
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Frequency
X-Band
Array
1m x 1m
Average Beam Width
2ox 2o
Azimuth Scan Range
±45oto ±60o
Elevation Scan Range
0o–20o(< 3 km)
0o–56o(22 km coverage)
Dual linear transmit and receive polarization
Performs electronic beam steering in azimuth direction while mechanically steering (tilting) the antenna in the elevation direction
TR Modules
PS
A
PS
A
PS
A
PS
A
PS
A
PS
A
Passive Antenna
Power Divider / Combiner
Reference: AFFORDABLE PHASED ARRAY WEATHER RADARS: STARTING TO BECOME A REALITY, by Prof. David J. McLaughlin, Engineering Research Center for Collaborative Adaptive Sensing of the Atmosphere (CASA), Department of Electrical and Computer Engineering, College of Engineering, University of Massachusetts

19. DTRM FROM MISTRAL
•
GaN based Dual Transmit Receive Module (DTRM)
•
RF Frequency Range: 3.1 to 3.5 GHz
•
Transmit Output Power Level: 100W
•
Receiver Input Power protection: 100 W, 200usec, 20%Duty
•
Dimensions (in mm for DTRM): 220x93x33mm
•
Weight (DTRM): < 1000 grams
•
Operating Temperature: -20C to +55C
•
Cooling: Surface finish for Liquid cooling
onanexternal cold plate
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20. SYSTEMS ENGINEERING
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Mistral Confidential
20
Complex Application Platforms
Liquid-cooled, Air-cooled and
Conduction-cooled systems
Integration of Multi-Vendor COTS Solutions,
SW, HW and RF Engineering
Qualification and Field Trials
Production, Deployment and Maintenance
1
2
3
4
5
Electronic Warfare
Airborne Telemetry
SONAR
RADAR

21. SERVICES OFFERED
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Complex Application Platforms
Liquid-cooled, Air-cooled and Conduction-cooled systems
Integration of Multi-Vendor COTS Solutions, SW, HW and RF Engineering
Qualification and Field Trials
Production, Deployment and Maintenance
1
2
3
4
5

22. THANK YOU
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23. Mistral Solutions Pvt. Ltd.,
No.60, 'Adarsh Regent',
100 Ft. Ring Road, Domlur Ext,
Bangalore - 56 0 071 India
Tel: +91-80-3091 2600
Mistral Solutions Inc.,
4633 Old Ironsides Drive,
Suite 410,
Santa Clara, CA 95054, USA
Phone: +1-408-705-2240
E-mail: info@mistralsolutions.com