Contribution à l'étude d'antennes miniatures multi-bandes.

Abstract

The work of this thesis is part of the continuity of research on antennas both miniature and multi-band. The first part is devoted to the theoretical study of the antennas that apply in the field of telecommunications, different techniques of miniaturization and multi-band technology. Turning to the description of the finite difference method in the FDTD time domain, this method and two other software programs (the Ansoft HFSS and the CST Microwave Studio) are used to calculate the electromagnetic characteristics and to study the effects of certain parameters on the performance of planar rectangular monopole antennas with a slot and two slots. The second area of research focuses on the development of original miniature antennas that can meet the needs of today's wireless systems based on slot insertion and the use of fractal shapes to reduce the size of antenna. The first structure is an antenna with ground plane slots that operates in two bands at 2.4 GHz (WLAN) and 3.75 GHz (WiMAX). The second flower-shaped fractal antenna with a defective ground plane provides three 2.4 GHz (Bluetooth), 3.6 GHz (WiMAX) and 5.8 GHz (WLAN) resonance frequencies.