Much of the work of this thesis was guided by the demands of the working group on antennas broadband arrays of the " GDR Ondes ". This work concerns the design of very thin UWB planar array antennas above a ground plane. The frequency range which is allocated by the Federal Communications Commission (3.1-10.6GHz) for telecommunication applications has been chosen. Firstly in this work we defined the array factor in frequency and time domains. Then we have constructed a facility test to measure antennas in both frequency and time domains. A novel planar antenna has been designed and constructed to provide a radiation in a half space. The antenna is formed by a rectangular slot etched in the center of a metallic ground plane. A metallic cavity with the same dimensions of the slot is placed behind the antenna. The gain, the impulse response, the fidelity factor, the pulse duration and pulse shape of the proposed antenna has been simulated and measured. A comparison with results from other antennas has been conducted. Finally, this work has led to the realization of two planar array antennas with high gain used in communications systems and in pulsed mode.
