Contribution a l’ Optimisation de la Synthese des Antennes Intelligentes par les Reseaux de Neurones (contents in French)

An intelligent antenna is actually composed of a series of elementary antennas (linear, circular, etc.) who?s received signals are balanced and combined by using a technique of adaptation in order to control and improve the reception or the transmission. The objective of our study is to look further into the knowledge of the methods of formation of the beams and to elaborate a digital technique of synthesis for the formation of ways and the cancellation of interfering which answers the specifications imposed by the system adaptive by using the networks of neurons. The work of thesis consisted of a contribution to the optimization of the lobe of radiation for an intelligent antenna. In a first stage, two complementary approaches were developed to implement the technique of forming of the lobe, one based on an algorithm of optimization which calculates the phases of the excitations according to the specifications desired (pointed lobe, multi-lobes, creation of the zeros) and the other using the results of the first technique to implement a model with neural networks. The first method has a disadvantage concerning the computing time (some seconds the second is almost an application in real time and to validate our concept in second stage, two antennas array (patch and quasi-Yagi) were produced. Finally, the phases of the excitations were implemented directly on an electronic platform dedicated to the placement of an intelligent antenna and a practical validation was carried out. Many measurements of antenna array (8 elements), excited only in phase, made it possible to validate our developed tools.