1 Institut für Grundlagen der Elektrotechnik und Messtechnik Sven Fisahn Cost 286 Workshop on „EMC Aspects of Wireless Communications in Transport Systems” Analysis of Leaky Section Cables for Multi-Band Aircraft Cabin Communications with different Measurement Techniques Sven Fisahn 1 , Michael Camp 1 , Núria Riera Díaz 2 , Robert Kebel 3 , Heyno Garbe 1 1 Institut für Grundlagen der Elektrotechnik und Messtechnik, Universität Hannover 2 Institut für Kommunikation und Navigation, Deutsches Zentrum für Luft- und Raumfahrt 3 Lightning Protection and Electromagnetic Compatibility, Airbus Deutschland GmbH e-mail: [email protected]
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1 Institut für Grundlagen der Elektrotechnik und Messtechnik Sven Fisahn Cost 286 Workshop onEMC Aspects of Wireless Communications in Transport Systems.
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1Institut für Grundlagen der Elektrotechnik und Messtechnik
Sven Fisahn
Cost 286 Workshop on„EMC Aspects of Wireless Communications in Transport
Systems”
Analysis of Leaky Section Cables for Multi-Band Aircraft Cabin Communications with different
Measurement Techniques
Sven Fisahn1, Michael Camp1, Núria Riera Díaz2, Robert Kebel3, Heyno Garbe1
1 Institut für Grundlagen der Elektrotechnik und Messtechnik, Universität Hannover 2 Institut für Kommunikation und Navigation, Deutsches Zentrum für Luft- und Raumfahrt 3 Lightning Protection and Electromagnetic Compatibility, Airbus Deutschland GmbH
• LSC functions both as a transmission line and as an antenna leaky section non-leaky section
• System integration process requires detailed information about radiation and transmission behaviour and interference potential
4Institut für Grundlagen der Elektrotechnik und Messtechnik
Sven Fisahn
Measurement Setup (Open Area Test Site)
DLR test site in Oberpfaffenhofen (Germany)• Circular far field radiation pattern• Vertical and horizontal polarization• CW-signals (700 MHz to 2.5 GHz)
5Institut für Grundlagen der Elektrotechnik und Messtechnik
Sven Fisahn
Measurement Setup (GTEM Cell Measurement)GTEM 1250 at GEM, University of Hannover• Circular near field radition pattern• CW-signals (450 MHz to 6 GHz)• cable length 1 m, includes 1 leaky section
6Institut für Grundlagen der Elektrotechnik und Messtechnik
Sven Fisahn
Measurement Setup (Near Field Scanning)
Near field measurements at GEM, University of Hannover
• Distribution of electric field strength along the cable
CW-signals (450 MHz to 6 GHz)• Radiation at front side and back side
of LSC
Transient signals (rise time: 5 ns)• Conical and biconical field probes
7Institut für Grundlagen der Elektrotechnik und Messtechnik
Sven Fisahn
Measurement Setup (Attenuation)
Attenuation measurement at GEM, University of Hannover
9Institut für Grundlagen der Elektrotechnik und Messtechnik
Sven Fisahn
Measurement Results (Transient Signal)
Comparison of the spectral energy distribution
106
107
108
109
10-12
10-10
10-8
10-6
Spectral energy distributionInput (---- blue)Output (---- red)
|U(j)| / (V/m/Hz)
f / Hz
• Identical characteristics of both spectra• Pulse shape nearly unaffected by transmission through
leaky section cable
10Institut für Grundlagen der Elektrotechnik und Messtechnik
Sven Fisahn
Measurement Results (Transient Signal)
Radiation measurement with conical field probe
0 0.5 1 1.5 2 2.5 3
x 10-7
-100
0
100
200
300
Electrical field at leaky side
t / s
E(t) / (V/m)
0 1 2 3 4 5
x 10-7
-100
-50
0
50
100
Electrical field at back side
t / s
E(t) / (V/m)
• Electric field strength much higher on leaky side
11Institut für Grundlagen der Elektrotechnik und Messtechnik
Sven Fisahn
Measurement Results (Transient Signal)
Spectra of radiated electric field
0 2 4 6 8 10
x 108
0
1
2
3
4x 10
-10
f / Hz
|E(j)| / (V/m/Hz)
Electrical field at leaky side
0 2 4 6 8 10
x 108
0
1
2
3
4x 10
-10
f / Hz
|E(j)| / (V/m/Hz)
Electrical field at back side
• Spectral energy distribution < 1 GHz reduced • Spectral energy distribution > 1 GHz very similar• Discrete frequencies (75 MHz, 150 MHz, 225 MHz,...)
12Institut für Grundlagen der Elektrotechnik und Messtechnik
Sven Fisahn
Measurement Results (CW-Signal, OATS)
Circular radiation pattern via OATS• Four distances d from the cable axis at 2 GHz
• Single and wide main lope for parallel polarization• Zeros at 0 and 180 deg. for perpendicular polarization
13Institut für Grundlagen der Elektrotechnik und Messtechnik