Multifunction Phased Array Radar Advanced … · David Conway 5 December 2017 Multifunction Phased Array Radar Advanced Technology Demonstrator Sponsors: Mike Emanuel, FAA ANG-C63

David Conway

5 December 2017

Multifunction Phased Array RadarAdvanced Technology Demonstrator

Sponsors: Mike Emanuel, FAA ANG-C63Kurt Hondl, NSSL

Lincoln Laboratory Air Traffic Control Workshop 2017MPAR ATD - 25 December 2017

Multifunction Phased Array Radar (MPAR) for Aircraft and Weather Surveillance

• 9 Radar System Designs• Rotating Dish Technology• Many Nearing End-of-Life

ASR-8 ASR-9 ASR-11Terminal Area Aircraft

NEXRAD

Long Range Weather

TDWR

Terminal Area Weather

Current Aircraft and Weather Radars

Multifunction Phased Array Radar

Long Range AircraftARSR-1/2 ARSR-3 ARSR-4 FPS-20/66/67

• Lower Life Cycle Cost– Reduced radar count from > 600 to 400– Lower O&M (no moving parts)– Streamlined training and sparing

infrastructure• Increased performance benefits

– Adaptive Scan Strategies– Higher sample rates


Adaptive Beam Scanning


Phased Array Advantages for Weather Sensing

1 minute Updates (e.g. MPAR Requirement)

4 minute Updates(e.g. NEXRAD Rate)

• Set-Up– Two forecasting teams

presented video clips from data set

– Clips differed by the update rate

o 4 min for NEXRADo 1 min for MPAR

• Result– Median difference in

tornado declaration time ~ 20 minutes earlier for the higher sample rate loop

Tornado Track

Fast Update RateSlow Update Rate


Design Concept

Frequency: S-Band (2.7 – 3.1 GHz)Diameter: 4m & 8mT/R Modules/Face: 5,000 / 20,000Beamwidth: 2 / 1°Bandwidth: 5 MHzPeak power: 16 W / elementPolarization: Dual linear/circular

Array cost/m2: $60K / m2

• Panel-based Aperture• Polarization Diverse for Weather• Multiple Beams for Timeline

Weather(1 dual pol beam)

Aircraft Surveillance

Weather Surveillance

Two 6 x 2 beam clusters

Aircraft(up to 24 linear pol beams)

EASY

HARD

Key Challenge: Reduce array cost from current $1M / m2 to $60K / m2

T/R = Transmit / Receive


FY 07-11• T/R Module and

Aperture Printed Circuit Board (PCB) Assembly development

• Custom integrated Circuit (IC) chip set development

FY 13-15 • Polarimetric

Performance• Digital beam

clusters• Verify thermal

management

• Initial radar testing

FY 12-13• Component re-

spin• “Tileable”• Backplane

design• Thermal Design

• Range testing

FY15-18• Terminal MPAR

Size, 4m• Real time radar

backend• Aircraft/ Weather

Processing• Specification

Development

Development Timeline

MPAR ATDPerformance Assessment

Gen2 PanelsGen1 Panel

2 PanelSubarray

10 Panel Demonstrator

76 Panel Advanced Technology

DemonstratorFirst Panel


Gen1 Aperture PCB Assembly

Overlapped Digital Subarray

Beamformer

Dual Polarized Balance–feed Stacked Patch

Dual Pol, 6W/Pol T/R Module< $25 at volume

Heat Sink

Top View Bottom View

Critical Technologies

16”

Fully populated 64 element Aperture PCB Assembly • Dual simultaneous polarization• 2.7 – 2.9 GHz operating band• Transmit and receive functionality

PCB = Printed Circuit BoardT/R = Transmit / Receive






• Initial cost/performance data




management





• Range testing





Development



2 PanelSubarray



DemonstratorFirst Panel


MPAR Panel

Air Flow

AperturePCB

T/RModules Standoffs

DC/LogicInterconnects

BackplanePCB

TxDriver

Panel Structure


Ten Panel Demonstrator System Components / Set-up for String Testing on Hanscom Runway

String Testing of 10 Panel Demo


• “Birdbath” Mode• Looking up, rain drops are

always round!

Polarimetric Radar Measurements

Bright Band






• Initial cost/performance data




management





• Range testing





Development



2 PanelSubarray



Demonstrator (ATD)First Panel


Advanced Technology Demonstrator(ATD)

• 4,864 element array (76 Panels)• 58 kW peak radiated power• 2.7-3.1 GHz• Dual polarization• 48 digital receiver channels• Real time processing• Shipment to NSSL February 2018

4 mNational Weather Radar

Testbed (NWRT)Norman, OK


Radar Testbed Interior Layout

Radar Backend:Receivers, Exciters,

Digital Signal Processing (DSP)

• Azimuth Rotary Platform

• System Power• HVAC

MIT-LL Lead

48VDC Rectifier Banks

Pedestal and Elevation rotator

Antenna Array

Beam-Steering Generator (Array

Control Computer)

Application Software


ATD Assembly, Integration, and Test

Cable/BeamformerFab & Test

Antenna Frame

Alignment

Install Cables/

Beamformers

Backplane Testing Panel Testing

Install Panels

Antenna Testing

(Phase 1)

Radar Testing

(Phase 2)

Integrate Backend

Electronics


Array Installation in Nearfield Chamber


First ATD Tests: Element Health Check

Array Viewed from Non-Radiating Side

• Each element measured one at a time using remote probe

• Measurement time for all elements, all modes: <30 minutes

• Tests repeated roughly once per day.

Remote probe


Reference State Data Collect

• Nearfield probe moves directly in front of element-under-test

• Insertion gain and phase measured for each element in the array at its reference state

• Data used for precision electrical alignment of all elements in the array

Rx Ref. State Amplitude

Rx Ref. State Phase


Nearfield-to-Farfield Transform (NF2FF)

NF2FF

• Raw NF scan data is on a regular 2-D grid plane (physical space)

• Data is transformed to Farfieldpattern using FFT-based process

• Antenna FF Pattern is adjusted using waveguide probe calibration dataset (“Probe Compensation”)

NF = Nearfield FF = FarfieldFFT = Fast Fourier Transform


Next Steps

Delivery

• Disassembly of system• Shipment to NSSL• Installation on site

Integration and Test

• Calibration and alignment• Design Verification Test• Initial Operational

Capability

Operation

• Polarimetric radar calibration

• Weather• Severe storm science


• MIT Lincoln Laboratory is developing, building, testing and fielding a 4-meter S-band dual-polarization active phased array antenna

• The MPAR ATD is the culmination of work sponsored by the FAA and NOAA since FY 2007 on low-cost active phased array technology– ATD development has informed FAA investment decisions for Next

Generation primary aircraft surveillance– The ATD will serve as the primary weather research asset for the

National Severe Storms Laboratory in Norman, Oklahoma

Summary


Legal Notices

Distribution Statement: Approved for public release; distribution is unlimited.

This material is based upon work supported by the National Oceanic and Atmospheric Administration and the Federal Aviation Administration under Air Force Contract No. FA8721-05-C-0002 and/or FA8702-15-D-0001. Any opinions, findings, conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Oceanic and Atmospheric Administration or the Federal Aviation Administration.

© 2017 Massachusetts Institute of Technology.

Delivered to the US Government with Unlimited Rights, as defined in DFARS Part 252.227-7013 or 7014 (Feb 2014). Notwithstanding any copyright notice, U.S. Government rights in this work are defined by DFARS 252.227-7013 or DFARS 252.227-7014 as detailed above. Use of this work other than as specifically authorized by the U.S. Government may violate any copyrights that exist in this work.

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Multifunction Phased Array Radar Advanced … · David Conway 5 December 2017 Multifunction Phased Array Radar Advanced Technology Demonstrator Sponsors: Mike Emanuel, FAA ANG-C63