par study-1 jsh 3/28/2005 mit lincoln laboratory multifunction phased array radar (mpar) jeffrey...

PAR Study-1JSH 3/28/2005

MIT Lincoln Laboratory

Multifunction Phased Array Radar (MPAR)

Jeffrey Herd

Mark Weber

MIT Lincoln Laboratory

20 March 2007

MIT Lincoln LaboratoryPAR Study-2

JSH 3/28/2005

Outline

• Introduction to MPAR Concept

• MPAR Pre-Prototype

• Development Roadmap

• Summary


JSH 3/28/2005

• Aging mechanically scanned radars

• 8 unique types for 4 different missions

• Over 500 total with redundant spatial coverage

Today FutureASR-9ASR-9

ASR-11ASR-11

ARSR-3ARSR-3

TDWRTDWR

ARSR-4ARSR-4

National Air Surveillance Infrastructure

• State-of-the-art active phased array radars

• 1 type for all missions: Multifunction Phased Array Radar (MPAR)

• Efficient coverage and support infrastructure by eliminating redundancy

ASR-8ASR-8

ARSR-1/2ARSR-1/2

NEXRADNEXRAD


JSH 3/28/2005

Current Capabilities

Maximum Detection Range

CoverageAngular

ResolutionWaveform

Scan PeriodAircraft

1 m2

Weather0 dBZ

Range Altitude Az. El.

Terminal Area Aircraft

Surveillance(ASR-9/11)

60 nmi 12 nmi 60 nmi 20,000' 1.4 5o

>18 pulsesPRI ~0.001

sec5 sec

En Route Aircraft

Surveillance(ARSR-4)

205 nmi 5 nmi250 nmi

60,000' 1.4 2.0>10 pulsesPRI ~0.001

sec12 sec

Terminal Area Weather(TDWR)

195 nmi 100 nmi 60 nmi 20,000' 1 0.5~50 pulsesPRI ~0.001

sec180 sec

En Route Weather

(NEXRAD)210 nmi 85 nmi

250 nmi

50,000' 1 1~50 pulsesPRI ~0.001

sec>240 sec


JSH 3/28/2005

Concept MPAR Parameters

• Active Array (planar, 4 faces)Diameter: 8 mTR elements/face: 20,000Dual polarizationBeamwidth: 0.7 (broadside)

1.0 (@ 45)Gain: > 46 dB

• Transmit/Receive ModulesWavelength: 10 cm (2.7–2.9 GHz)Bandwidth/channel: 1 MHzFrequency channels: 3Pulse length: 1–100 sPeak power/element: 1–10 W

• ArchitectureOverlapped subarrayNumber of subarrays: 300–400Maximum concurrent beams: ~160

• Active Array (planar, 4 faces)Diameter: 8 mTR elements/face: 20,000Dual polarizationBeamwidth: 0.7 (broadside)

1.0 (@ 45)Gain: > 46 dB

• Transmit/Receive ModulesWavelength: 10 cm (2.7–2.9 GHz)Bandwidth/channel: 1 MHzFrequency channels: 3Pulse length: 1–100 sPeak power/element: 1–10 W

• ArchitectureOverlapped subarrayNumber of subarrays: 300–400Maximum concurrent beams: ~160

Aircraft Surveillance

Non cooperative target tracking and characterization Weather

Surveillance


JSH 3/28/2005

CONUS Coverage

1000ft AGL

5000ft AGL

Legacy Air Surveillance Coverage Multifunction Radar Coverage

* Gapfiller and full aperture antenna assemblies to save cost

510 Total Radars, 7 unique types 334 Total Radars, 1 type*

35% reduction


JSH 3/28/2005

Preliminary Life Cycle Cost Comparison

• Replacement of legacy systems with MPAR on as-needed basis saves ~ $2.4B over 20-year period

• Majority of savings comes from reduced O&M costs

• Replacement of legacy systems with MPAR on as-needed basis saves ~ $2.4B over 20-year period

• Majority of savings comes from reduced O&M costs

• Assumptions:– 510 legacy @ $5-10M ea– 167 full-size MPAR @ $15M ea– 167 terminal-area MPAR @ $5M ea– Legacy O&M = $0.5M per year– MPAR O&M = $0.3M per year

$2.4B


JSH 3/28/2005

Tx Peak Power vs. Pulse Compression

10 W / element

Compression ratio = 10

1 W / element

Compression ratio = 100

TDWRSTC On

• Sensitivity ~ PpNG2

~ PpN3

• Module cost ~ Pp

Keep Pp small, increase N and lengthen as needed (with pulse compression for range resolution)

• But long requires short “fill” pulse for close-range coverage: crucial for terminal-area surveillance

• Sensitivity ~ PpNG2

~ PpN3

• Module cost ~ Pp

Keep Pp small, increase N and lengthen as needed (with pulse compression for range resolution)

• But long requires short “fill” pulse for close-range coverage: crucial for terminal-area surveillance

MPAR Weather Sensitivity

Pp: Peak power per element N: Number of elements per face G: Antenna gain : Pulse length

For 46-dB MPAR antenna gain


JSH 3/28/2005

Fill-Pulse and Long-Pulse Sensitivity

NEXRAD@ 230 km for long pulse

@ end of fill-pulse range

-15 dBZAssumes 46-dB antenna gain

> 2W per element with 30 s long-pulse and 1 s fill-pulse lengths meets sensitivity requirements

> 2W per element with 30 s long-pulse and 1 s fill-pulse lengths meets sensitivity requirements~

MIT Lincoln LaboratoryPAR Study-10JSH 3/28/2005

• Current civilian ATC primary radars do not measure target altitude

– Cooperative (beacon) response is used

• Proposed ADS-B ATC surveillance is entirely cooperative

– MPAR could be used for 3D detection/tracking of noncooperative targets, and back up & verification for ADS-B

• Current civilian ATC primary radars do not measure target altitude

– Cooperative (beacon) response is used

• Proposed ADS-B ATC surveillance is entirely cooperative

– MPAR could be used for 3D detection/tracking of noncooperative targets, and back up & verification for ADS-B

• High PRF and full bandwidth for target characterization

• Target ID mode has limited range swath and cannot operate concurrently with other modes

• Would be used in brief “point and ID” bursts based on external cues

• High PRF and full bandwidth for target characterization

• Target ID mode has limited range swath and cannot operate concurrently with other modes

• Would be used in brief “point and ID” bursts based on external cues

0 10 20 30 40 50 60 70 80 90

Clutter

Fuselage

Engine Harmonics

Clutter

Fuselage

Engine Harmonics

Relative Range (m)

300

200

100

0

100

200

300

Vel

oci

ty (

m/s

)

Height Discrimination

ATCRBS reply quantization

Mode S reply quantization

Target ID

MPAR with monopulse

Noncooperative Target Surveillance:3D Tracking


Outline




• Summary


Notional MPAR Pre-Prototype System

4.2 m

4.2 m

= element

= subarray center

4544 elements284 bricks16 subarrays8 X 1 beam cluster

= brick

• Pre-Prototype radar demonstrates two simultaneous modes

– Aircraft and weather surveillance– Beamwidth: ~ 2º az by 2º el (broadside)– Two independent beam clusters

Electronic steering ±45º az, ±40º el Up to 8 beams in each 1D cluster

– Provides terminal area coverage to @140 km (8 W per element, 20 sec pulse )

Subarray

16SubarrayPhaseCenters


MPAR Pre-Prototype Systems Analysis

b

• Trade off between HPA power, pulse compression ratio, and minimum detectable reflectivity

• Desired performance achieved with 8W and 20:1 pulse compression


Multiple Beam Cluster Array Architecture

1

1 N

Digital Beamformer

Switched Dual Pol

Radiators

Dual-Mode T/R Modules

M

Overlapped Subarray Beamformer

Dual Mode Transceivers

Freq 1 Freq 2

f1 f2

Channelizer

HPA LNA

Channelizer

Beam Clusters

2

f1 f2

Channelizer

HPA LNA

Channelizer

f1 f2

Channelizer

HPA LNA

Channelizer

Analog Beamformer

Digital Receiver Digital Receiver

Real Time Beamformer

Back End ProcessorRadar Signal Processors

analog

digital

Beamsteering Controller


Modular Brick

‘Brick’ Array Architecture

• Brick approach provides low cost, scalable architecture

• Open frame concept for easy access– Forced air cooling

• Chassis modularity– Flexible brick arrangements

Standard Eurocard Format

T/R Modules

T/R Module Card


Transient Thermal Analysis

• Transient thermal analysis– 2W, 4W, 8W, 10W peak transmit amplifiers– Varying pulse lengths

• Includes critical chip level details– Thermal conductivities of device and interfaces

• 8W peak power with 20 µsec pulse is thermally acceptable

Forced AirHPA’s

Physical Geometry

Time, µsec

Te

mp

era

ture

, C

85 ° C

Thermal Modelling Transient Response

T/R Card


Dual Mode T/R Module

• T/R Module design supports two independent beam clusters

• ‘Pick and place’ surface mount parts reduce packaging / assembly costs

• Custom RF designs for application-specific components

Red = Off the Shelf partsBlue = Custom Parts

To Element V-Pol Feed

To Element H-Pol Feed


8W T/R Module Parts Costs

• Parts costs driven by HPA chips and PC board fabrication

• Packaging / test costs not included

• Current HPA chip costs are nearly linear with RF power

Item Quantity Unit Cost Total CostHPA 2 $23.00 $46.00Bias 1 $15.00 $15.00SP2T 3 $4.00 $12.00LNA 1 $1.69 $1.69BPF 1 $3.00 $3.00Diplx 1 $1.50 $1.50Vect Mod 3 $2.14 $6.42Driver 1 $2.50 $2.50Load 1 $2.00 $2.00Board 1 $25.00 $25.00 Total = $115.00

v


T/R Module Components

• T/R module utilizes COTS and custom components– Use custom parts only when it reduces cost, or if not

available as COTS part

COTS Evaluation Boards

Vector Modulator Diplexer

Combline Filter

Custom RF Components

LNA

Switch (T/R and Pol)HPA Bandpass Filter PC Board


T/R Module Status

Action Status Remarks

Select COTS components

Order COTS evaluation parts

Design custom components

Layout custom boards

Fabricate custom parts Delivery late March

Test COTS evaluation parts Waiting for several parts

Test custom parts Waiting for board fab

Assemble connectorized module

Test fully assembled module


Overlapped Subarray Beamformer

• Overlapped subarray enables multiple beam clusters

• Tradeoff between analog and digital complexity

• Prototype X band overlapped subarray successfully demonstrated under MIT LL IR&D

– S band version currently in fabrication

RadiatingElement

Weighted 1:3 Divider

Weighted 1:3 Combiner

A1 A2 A3 A1 A2

Subarray Output

Subarray Output

Subarray Output

A1 A2 A3 A1 A2 A1 A2 A3 A1 A2

Weighted 1:4 Combiner

Overlapped Subarray Architecture Passive Beamformer Layout

v


Overlapped Subarray Beamformer on RFIC Chip

Measured RFIC Beamformer Pattern

• RFIC beamformer reduces cost, size and weight

• Programmable weights enable optimized beam patterns and advanced calibration

• Prototype X band RFIC demonstrated under MIT LL IR&D

RFIC CMOS Beamformer Chip

12 Element X band Subarray

IdealMeasured


Dual Mode Receiver

• Parts evaluation confirms discreet component performance– SFDR = 70 dB, NF = 5.3 dB, OIP3=34 dBm– Parts costs = $225

• EMI modeling and testing of surface mount boards is critical

Dual Mode Receiver Architecture Bench Test Dual Mode Receiver

v


Digital Subarray Beamformer

8 Digital Beam Cluster

• Processing simulation tool developed for Pre-Prototype MPAR– Identified critical kernels

• 16 channel FPGA testbed to test and evaluate kernel designs

Digital Beamformer Architecture

v


Preliminary Parts Cost Estimates

Component Pre-Prototype Full Scale MPAR

Antenna Element $1.25 $1.25

T/R Module $115.00* $40.00**

Power, Timing and Control $18.00 $18.00

Digital Transceiver $12.50 $6.25

Analog Beamformer $63.00 $15.00

Digital Beamformer $18.00 $8.00

Mechanical/Packaging $105.00 $25.00

RF Interconnects $123.00*** $40.00****

Equivalent Cost per Element - Parts Only

$455.75 $153.50Totals:

* Assumes 8W module incl RF board with sequential polarization

** Assumes 2W module incl RF board with sequential polarization*** Assumes standard beamformer in azimuth**** Assumes hybrid tile/brick architecture


Outline




• Summary


Notional MPAR Pre-Prototype Development Schedule

Year 1 Year 2 Year 3 Year 4

Concept Development, Design, and Subsystem

Prototyping

Concept Development, Design, and Subsystem

Prototyping

System Fabrication and

Assembly

System Fabrication and

Assembly

Experimental Testing and Evaluation

Experimental Testing and Evaluation

CDRPDR Testing CDR

• 16 Element Brick• Transceiver

• Waveform Design• Systems Analysis

• 80 Element Subarray• Digital Beamformer DBF)

• Algorithm Dev • System Simulation

• 4544 Element Array• 16 Channel DBF

• System Simulation• Test Planning

• Collect Multimode

Data

• Process Data • Report Results

Analog and Digital Hardware:

Systems Analysis & Signal Processing:

Brick Subarray Array Data Collection


Summary

• Key MPAR features– Lower O&M costs– Scalable– Multifrequency– Dual polarization– Digital beamforming (multiple receive beam clusters) – Adaptive control– Low module peak power– Auxiliary mode functions

• MPAR Pre-Prototype Technology Demonstration Program– Shows path to ultra-low cost implementations– Provides a means to develop and test MPAR concept– Solidifies key technical requirements

• Critical demos provide early performance and cost data – Dual mode T/R module– Overlapped subarray beamformer– Dual mode receiver– Digital beamformer– Thermal management

par study-1 jsh 3/28/2005 mit lincoln laboratory multifunction phased array radar (mpar) jeffrey...

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