This thesis is part of a collaboration between IM2NP and Tagsys, as part of the PACID-TEXTILE project. The aim of the thesis is to create a packaged, highly robust UHF RFID tag that can be easily and discreetly integrated into textile products. The idea is to design two antennas coupled and adapted to the chips chosen for the application. These two antennas are designed to promote coupling between them. The first entity is packaged to protect the chip from the operating environment. In the first part, the primary antenna is characterized. The packaging is the subject of special studies to meet the robustness constraints associated with the textile industry (laundry, chemical products). The second part of the work aims to characterize the conductive wire so as to establish the most accurate model possible for use in antenna design and simulation tools. Wire resistance tests are also carried out. Finally, a third section deals with antenna design. The tags designed must have a minimum range of 4m, resist deformation and stacking. These tags are subjected to various tests to establish their performance. Using the characterization resources available at the IM2NP laboratory (RFID pre-certification platform), a "Benchmarking" exercise is carried out on the various tags, with a view to proposing a tag that best meets the requirements of the specifications.