Effects of random RF disturbances on aeronautical communication systems

Air Traffic Control (ATC) and their responsible authorities have been always very sensitive to safety of the systems they are using to guarantee a fool-proof and environmentally safe operation of the facilities to provide air traffic services and guidance for the airplanes. This paper deals with the influence of random systems like badly shielded ignition systems of cars and motorbikes on standard air-ground aviation communication systems. Following a series of theoretical simulations, a measurement campaign quantifying this influence is described. This campaign is shedding some light on the fundamental behaviour and mechanisms of the RF disturbances caused by (shielded and unshielded) spark plug systems. It will be investigated both in the time domain and in the frequency domain. An analysis of the inaccuracies of those measurements is performed and the influence of (shielded and unshielded) spark plug systems on aviation communication systems (still based on A(mplitude)M(odulation)) is explained in detail

Effects of pulsed RF disturbances on aeronautical communication systems

Air Traffic Control (ATC) and their responsible authorities have been always very sensitive to safety of the systems they are using to guarantee a fool-proof and environmentally safe operation of the facilities to provide guidance for the airplanes. This paper deals with the influence of a pulsed systems on standard air-ground aviation communication systems. A measurement campaign is described. An analysis of the inaccuracies of those measurements is performed and the influence of (shielded and unshielded) spark plug systems on aviation communication systems (still based on A(mplitude) M(odulation)) is explained in detai

Performances of conformal and planar arrays

Static and dynamic deformations can have a severe impact on the performance of conformal antennas on aircrafts and other vehicles. Therefore it is essential to study the different deformation and vibration mechanisms and their influence on the antenna's radiation pattern. This presentation gives an overview of different approaches concerning electromagnetic modelling of array antennas and investigations on antenna deformations presented in the scope of TG20

On the worst case trajectories of microwave links above Belgium

It is common that the national authorities impose large consultation zones around microwave links [1]. When those areas are free of obstacles there is no problem, but usually they are considered as exclusion zones. Those large zones are inspired by the fact that the obstacle for which the authorisation is requested may not be the only one, especially in the case of wind turbines. The national authorities (for Belgium BIPT/IBPT) impose limitations on the projections of the links in a horizontal plane, usually 3 times the largest size of the first Fresnel ellipsoid. In this paper we will investigate the 3D case to allow more lenient criteria to be applied.status: publishe

Non-separable Solutions of Helmholtz' equation revisited

Even if the idea is already very old (proposed first by Moseley in 1965), it offers analytical solutions of Helmholtz equations for curved waveguides. One of the key elements in their successful use is the computation of recursion formulas to find a numerical solution to the problem of analysis of generally shaped waveguides. They will be derived in this paper. Even if the original theory includes a generalisation to 3 dimensional cavities we will limit ourselves to 2 dimensional waveguide cases.status: publishe

On the worst-case influence of atmospheric circumstances on microwave links.

Some national authorities impose large consultation zones around microwave links [1]. When those areas are free of obstacles there is no problem, but usually they are considered as exclusion zones. Those large zones are inspired by the fact that the obstacle for which the authorisation is requested may not be the only one, especially in the case of wind turbines. The national authorities (for Belgium BIPT/IBPT) impose limitations on the projections of the links in a horizontal plane, usually 3 times the largest size of the first Fresnel ellipsoid. In this document, we will investigate the 3D case to allow the application of more lenient criteria.status: publishe

(Li-ion) batterijen & hun problemen

An overview is given of the fundamentals of batteries, as well as the problems encountered with specific Li-ion batteries.status: publishe

A statistical study of atmospheric circumstances on microwave links.

In a previous paper [1], we investigated the worst-case scenario of the influence of atmospheric circumstances on the propagation of microwave links. In this document, we will investigate this problem from a statistical point of view. This allows quantifying the probability of unlikely events to happen, and their impact on the quality of the transmission.status: publishe

Improving the wireless communication system at a large Antwerp car factory

The car factory experienced many communication problems within their factory, due to (new) requirements of the Belgian Federal Communication authorities (BIPT) to limit the height of the antennas to 12 m above ground level. This paper deal with the challenge to guarantee a 95% in this factory, with a large amount of moving metallic parts. The solution turned out to be an array of 4 antennas complemented with an auxiliary antenna.status: publishe

A Minimum BER Loading Algorithm for OFDM in Access Power Line Communications

In this paper, we investigate the resource allocation problem for access broadband power line communications (PLC) according to the OPERA specification for power grids monitoring and control. The proposed loading algorithm attempts to minimize the BER while guaranteeing a certain throughput for Amplitude Differential Phase Shift Keying (ADPSK) modulation, when the attenuation varies significantly in function of the frequency. A performance comparison between the proposed algorithm and the Fischer-Huber algorithm is also discussed. Numerical simulations show that the proposed method can improve the average BER performance.status: publishe