Fidele Moupfouma

In-Cabin Wideband Channel Characterization for WAIC Systems

The work presented here deals with in-cabin aircraft wireless channel characterization in a short-range aircraft. Both large-scale and small-scale parameters were extracted for 2.45 GHz and 5.8 GHz frequency bands. Results are analyzed and compared for multiple scenarios and for both line-of-sight (LOS) and non-line-of-sight (NLOS) situations. The mean path-loss exponents are 1.9 for 2.45 GHz and 1.6 for 5.8 GHz frequency bands which is different from some previous results obtained in relatively wide-body aircrafts. The mean coherence bandwidth determined for 2.45 GHz is 760 kHz while for 5.8 GHz it corresponds to 970 kHz. RMS delay-spread mean values lie around 19 to 33 ns for the lower band and 16 to 25 ns for the higher band. The statistical analysis revealed a delay-spread following lognormal distribution. Finally, the Rice model for LOS scenario, showed a better fit for the multipath fading envelope with an average-factor of 8.5 dB and 11 dB for 2.45 GHz and 5.8 GHz, respectively.

Portable electronic devices (PEDS) interference path coupling with aircraft mounted antennae test optimization

Not available for publication.

On the use of microwave microscopy for detecting defects in the lightning strike protection mesh for carbon fiber composite aircraft

In this paper we demonstrate the potential of using microwave microscopy for detecting defects in the lightning protection mesh used in composite aircraft skin. This technique has been proved capable of resolving defects as small as one missing wire mesh diamond of dimensions 3.1mm by 1.42mm. Paint thickness measurement was also identified as another possible application.

More wireless systems onboard of aircraft with metallic nanoparticles

Nowadays using Polymer Matrix Composites is the general direction in aeronautic industry. This approach has many advantages like. multi-functionality, simplicity and particularly weight issue. But these materials do not perform as metals in terms of electromagnetic shielding. Co-cured expanded metal (e.g. copper) foil inside composite has been chosen as the standard solution for mitigation. However composites with extended metal foil will loose the performance dramatically starting from a few GHz in HIRF environment. Studies done by RTCA. EUROCAE and certification authorities show the significant effects of wireless interference on avionic system of composite aircraft. Moreover front door coupling has been observed. The back door coupling is solved through HIRF certification but front door remains. Studies done by NIST show the low protection of composite aircraft against electromagnetic energy particularly in HIRF environment. Light weight EM shield for composite aircraft particularly in frequency range of concern (possibility of replacing the expanded metallic foil in certain zones by Nanotechnology solution) is needed because it appears to be the solution for limiting the risks related to the usage of wireless systems. Using the metallic nanoparticle inside the aircraft structure will provide more protected composite fuselage for a few GHz range of frequency and applying more wireless systems onboard of aircraft which has been studied in this work.