Ultra wide-band - UK test results

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Ultra Wideband UK Test Results
Presented by John Mettrop UK CAA
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What is Ultra WideBand?

• Short Duration Pulse
• Occupies significant Bandwidth (Normally
  gt500MHz)
• High Instantaneous Power
• Low average Power Flux Density
• Intended to Operate Below Noise Floor

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Ultra Wideband Applications (1)

• Communications
• 3.1 10.6 GHz
• Range lt30 Metres
• Bandwidth 480 MBits/Sec
• Replacement of USB, Video Streaming
• Ground/Wall Penetrating Radar
• lt 3 GHz
• Range lt2 cm to contact face
• Road/Runway/Wall Assessment
• Licensed and Co-ordinated

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Ultra Wideband Applications (2)

• Building Material Analysis
• lt 4 GHz
• Range lt1 Metre through Wall
• Location of Pipes/Cables/ Imperfections
• Intended to Be Unlicensed

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Theoretical Studies

• ITU
• TG1/8
• Established in 2002
• Completed its 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

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• Practical Testing in the UK

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Aggregate Effects?
Decreasing antenna gain
UWB Devices
300m
Radar Antenna
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Sidelobes
Azimuth beamwidth 2 to 4 degrees
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Antenna Elevation
Difference in antenna gain lt 1dB
One storey building
Two storey building
Handheld External?
Shielding Glass 0 dB Brick 10 dB dB
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Antenna Elevation
Difference in antenna gain lt 1dB
More important is number of devices rather than
height e.g. departure lounge. Eastleigh?
Shielding Glass 0 dB Brick 10 dB dB
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I/N versus UWB EIRP
Radar IF Filter Response
Single UWB spike e.g. 50 MHz PRF
Multiple UWB spikes e.g. 1.5 MHz PRF
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1.5 MHz Undithered, 1 MHz bandwidth
1.5 MHz Undithered
1 MHz bandwidth
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Dithered UWB
Undithered
Dithered
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Dithered UWB
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OFDM UWB
Bandwidth correction factor for noise-like
signals C 10log10(BW ratio) C 10log10(5)
7 dB BW Ratio Radar IF BW/1 MHz
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Effect of Radar Processing on Interference Type
Radar return pulse
20 dB
20 dB
50 MHz undithered spike
Frequency
20 dB
Radar return pulse
30 dB
OFDM
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False Targets Early Warning Mode
Targets start at 40 nm Target spacing 2.5 nm
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Determining Pd 1005 targets, no interference
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Determining Pd 804 targets
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Determining Pd 603 targets
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Determining Pd 402 targets
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Determining Pd 3 faint targets
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Pd vs EIRP Radar B Uncorrected
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Pd vs EIRP Radar A Uncorrected
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Correcting for wrong Pd
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Correcting for wrong Pd
Measured at 90 9.6 dB
Perform correction
Curve Fit Model for 90 9.6 dB At 50 point
Model
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Pd vs EIRP Radar B Corrected
-70 dBm/MHz at 358m
-90 dBm/MHz at 358m
-56 dBm/MHz at 358m
20 dB
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Pd vs EIRP Radar A Corrected
-53 dBm/MHz at 358m
-84 dBm/MHz at 358m
30 dB
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Distance correction
Antenna near field effects 100m?
First Fresnel Zone At 3 GHz gt 2 km
Field strength
ITU Propagation Models
20 Log D1/D2
40 Log D1/D2
Distance
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UWB Allowable Field strength vs Distance
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UWB Allowable Field strength vs Distance
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I/N versus EIRP UWB to Radar B
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Propagation Onset of UWB interference
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Key factors

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

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Faulty Baby Alarms

• Purpose
• Monitoring baby activity during sleep
• Potentially Affect Services
• VHF Communications
• Documented Cases of Interference
• Numerous in the UK
• Solution
• Supply replacement unit
• Studies
• None

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Industrial/Scientific/Medical 5th Harmonic of 27
MHz

• Purpose
• Various including RF drying ovens for biscuits
  etc
• Potentially Affect Services
• VHF Communications
• Documented Cases of Interference
• Numerous within the UK
• Solution
• Retune centre frequency of the RF unit
• Better RF Shielding
• Studies
• None

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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?
  docid1941wdN

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Wireless Cameras

• Purpose
• Wireless CCTV cameras
• Potentially Affect Services
• DME, SSR, GNSS
• Documented Cases of Interference
• See WG F Working Paper 9
• Solution
• Confiscation
• Prosecution
• Studies
• None

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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)

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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

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Windfarms 2
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• Questions