ACD A00000 00-01

Ultra WidebandUK Test Results

Presented by

John Mettrop

UK CAA

ACD A00000 00-01

What is Ultra WideBand?

Short Duration Pulse Occupies significant Bandwidth

(Normally >500MHz)High Instantaneous PowerLow average Power Flux DensityIntended to Operate Below Noise

Floor

ACD A00000 00-01

Ultra Wideband Applications (1)

Communications3.1 – 10.6 GHzRange <30 MetresBandwidth 480 MBits/SecReplacement of USB, Video Streaming

Ground/Wall Penetrating Radar< 3 GHzRange <2 cm to contact face Road/Runway/Wall AssessmentLicensed and Co-ordinated

ACD A00000 00-01

Ultra Wideband Applications (2)

Building Material Analysis< 4 GHzRange <1 Metre through WallLocation of Pipes/Cables/ ImperfectionsIntended to Be Unlicensed

ACD A00000 00-01

Theoretical Studies

ITU TG1/8 Established in 2002 Completed it’s work in 2005 Produce 1 report and 4 Recommendations

ECC PT 3 Report 64 ECC Decision Further Consultation on PFD Limits 3.1 – 4.4 GHz On-going Work on GPR/WPR/BMA Due to Complete June 2006

ACD A00000 00-01

Practical Testing in the UK

ACD A00000 00-01

Aggregate Effects?

Azimuth beamwidth ~2 to 4 degrees

Radar Antenna

Sidelobes

4°2°

~300m

UWB DevicesDecreasing antenna gain

ACD A00000 00-01

Antenna Elevation

Handheld External?

ShieldingGlass 0 dBBrick ~10 dB dB

One storeybuilding

Two storeybuilding

Difference in antenna gain< 1dB

ACD A00000 00-01

Antenna Elevation

ShieldingGlass 0 dBBrick ~10 dB dB

Difference in antenna gain< 1dB

More important is number of devices rather than heighte.g. departure lounge. Eastleigh?

ACD A00000 00-01

I/N versus UWB EIRPRadar IF Filter Response

Single UWB spike e.g. 50 MHz PRF

Multiple UWB spikes e.g. 1.5 MHz PRF

ACD A00000 00-01

1.5 MHz Undithered, 1 MHz bandwidth

1.5 MHz

-75

-70-65

-60

-55-50

-45

-40-35

-30

2999.5 2999.7 2999.9 3000.1 3000.3 3000.5

Frequency (MHz)

Lev

el (

dB

m)

1.5 MHz Undithered

1 MHz bandwidth

ACD A00000 00-01

Dithered UWB

-70

-60

-50

-40

-30

-20

-10

0

2992.5 2997.5 3002.5 3007.5

Frequency (MHz)

Leve

l (dB

m)

Dithered Undithered

Undithered

Dithered

ACD A00000 00-01

Dithered UWB

-80

-70

-60

-50

-40

-30

-20

-10

0

2992.5 2997.5 3002.5 3007.5

Frequency (MHz)

Leve

l (dB

m)

Sweep Time 30 ms; RBW 1 MHz Sweep Time 4 ms; RBW 1 MHz

Sweep Time 4 ms; RBW 100 kHz

ACD A00000 00-01

OFDM UWB

4.8 MHzchannel width

1 MHz measurement bandwidth Bandwidth correction factor

for noise-like signals:

C = 10log10(BW ratio)C = 10log10(5) = 7 dB

BW Ratio = Radar IF BW/1 MHz

ACD A00000 00-01

Effect of Radar Processing on Interference Type

Frequency

Radar return pulse

Radar return pulse

50 MHz undithered spike

OFDM

20 dB

20 dB

20 dB

30 dB

ACD A00000 00-01

False Targets: Early Warning Mode

Targets start at 40 nmTarget spacing 2.5 nm

ACD A00000 00-01

Determining Pd: 100%5 targets, no interference

ACD A00000 00-01

Determining Pd: 80%4 targets

ACD A00000 00-01

Determining Pd: 60%3 targets

ACD A00000 00-01

Determining Pd: 40%2 targets

ACD A00000 00-01

Determining Pd: 3 faint targets

1

23

ACD A00000 00-01

Pd vs EIRP: Radar B Uncorrected

Radar B

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

-60 -55 -50 -45 -40 -35 -30 -25 -20 -15 -10

EIRP (dBm/MHz)

Pd

CW 90% + 2.6 dB

CW 90% + 4.6 dB

50 MHz Und 90% + 4.6 dB

50 MHz Dith Peak 90% + 9.6 dB

15 MHz Und 90% + 9.6 dB

15 MHz Dith Peak 90% + 9.6 dB

5 MHz Und 90% + 9.6 dB

5 MHz Dith Peak 90% + 9.6 dB

1.5 MHz Und 90% + 9.6 dB

OFDM 90% + 9.6 dB

ACD A00000 00-01

Pd vs EIRP: Radar A Uncorrected

Radar A

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

-30 -25 -20 -15 -10 -5 0 5 10

EIRP (dBm/MHz)

Pd

CW 90% + 20.3 dB

50 MHz Und 90% + 20.3 dB

15 MHz Und 90% + 20.3 dB

15 MHz Dith Peak 90% + 20.3 dB

OFDM 90% + 20.3 dB

ACD A00000 00-01

Correcting for wrong Pd

ACD A00000 00-01

Correcting for wrong Pd

Measured at 90% +9.6 dB

Curve Fit Model for 90% + 9.6 dBAt 50% point

Perform correction

Model

ACD A00000 00-01

Pd vs EIRP: Radar B Corrected

-70 dBm/MHz at 358m

-90 dBm/MHz at 358m

-56 dBm/MHz at 358m

~20 dB

ACD A00000 00-01

Pd vs EIRP: Radar A Corrected

-53 dBm/MHz at 358m

-84 dBm/MHz at 358m

~30 dB

ACD A00000 00-01

Distance correction

First Fresnel ZoneAt 3 GHz > 2 km

Antenna near field effects~ 100m?

Field strength

Distance

20 Log D1/D2

40 Log D1/D2

ITU Propagation Models

ACD A00000 00-01

UWB Allowable Field strength vs Distance

-120

-100

-80

-60

-40

-20

0

0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000

Distance (m)

Leve

l dB

m/M

Hz

Pulsed (From) Pulsed (To) OFDM

FCC Limit at 3 GHz ECC Limit at 3 GHz UK Limit at 3 GHz

ACD A00000 00-01

UWB Allowable Field strength vs Distance

-120

-100

-80

-60

-40

-20

0

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Distance (m)

Leve

l dB

m/M

Hz

Pulsed (From) Pulsed (To) OFDM

FCC Limit at 3 GHz ECC Limit at 3 GHz UK Limit at 3 GHz

ACD A00000 00-01

I/N versus EIRP: UWB to Radar B

Radar B

0

5

10

15

20

25

30

35

40

-60 -50 -40 -30 -20 -10 0 10

EIRP (dBm/MHz)

I/N (

20 M

Hz

rbw

)

CW 1st IF Stage

50 MHz Und 1st IF Stage

50 MHz Dith Pk 1st IF Stage

15 MHz Und 1st IF Stage

15 MHz Dith 1st IF Stage

5 MHz Und 1st IF Stage

5 MHz Dith 1t IF Stage

OFDM 1st IF Stage

ACD A00000 00-01

Propagation: Onset of UWB interference

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

20

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Distance (m)

Leve

l dB

m/M

Hz

50 MHz Un-dithered 1.5 MHz Un-dithered OFDM

FCC Limit at 3 GHz ECC Limit at 3 GHz UK Limit at 3 GHz

ACD A00000 00-01

Key factors

Setting of targets to 90% Pd Determining when a target is visible IF measurement bandwidth Location of IF measurement in radar chain

ACD A00000 00-01

Faulty Baby Alarms

PurposeMonitoring baby activity during sleep

Potentially Affect ServicesVHF Communications

Documented Cases of InterferenceNumerous in the UK

SolutionSupply replacement unit

StudiesNone

ACD A00000 00-01

Industrial/Scientific/Medical 5th Harmonic of 27 MHz

PurposeVarious including RF drying ovens for biscuits etc

Potentially Affect ServicesVHF Communications

Documented Cases of InterferenceNumerous within the UK

SolutionRetune centre frequency of the RF unitBetter RF Shielding

StudiesNone

ACD A00000 00-01

Cable TV

Purpose Provision of television and internet services

Potentially Affect Services ILS, VOR, VHF Communications

Documented Cases of Interference Numerous in Germany and Belgium Initial Problems in the UK

Solution Improved termination of cables Frequency avoidance

Studies ECC Report 24 May 2003 http://www.ero.dk/documentation/docs/docfiles.asp?

docid=1941&wd=N

ACD A00000 00-01

Wireless Cameras

PurposeWireless CCTV cameras

Potentially Affect ServicesDME, SSR, GNSS

Documented Cases of InterferenceSee WG F Working Paper 9

SolutionConfiscation Prosecution

StudiesNone

ACD A00000 00-01

GSM On-board Aircraft

Purpose Provide mobile phone communications in flight

Potential Impact Interference to Aircraft Systems Passenger Behaviour (Air Rage) Interference to Ground Non-Aeronautical Services

Studies RTCA 202 (on-going) Eurocae WG58 (on-going) CEPT SE 7 Technical Report (on-going)

ACD A00000 00-01

Windfarms 1

Purpose Renewable Energy Provision

Potentially Affect Services Radar (ILS, MLS, VHF Communications)

Documented Cases of Interference See next slide

Solution Objection to Development

Studies None published Work on-going

ACD A00000 00-01

Windfarms 2

ACD A00000 00-01

Questions