HF surface wave radars (HFSWR) find applications in maritime surveillance, oceanography or target detection. They use HF waves (3-30 MHz) that propagate over the sea surface reaching a few hundreds of kilometers. Nevertheless, they are recent and not totally operational for the moment because of several drawbacks. The objective of this thesis is to solve 2 of these drawbacks to improve performance of HFSWR. First, one of the major constraints concerns the important size of the HF antennas. For practical reasons and to envisage a shipboard radar, it is necessary to design a compact HF antenna responding specifications of HFSWR. The first part presents the intellectual process that leads to the final prototype. Secondly, HF waves and sea surface interact and that creates important echoes that can hide echoes of potential targets. The second objective of this thesis is then to reduce the impact of these disturbing sea echoes thanks to an adaptative filtering method.
