SOCRATE

By focusing the radiation in useful directions, directional antennas offer new opportunities for wireless applications in terms of spectral efficiency, reduced environmental impact and use modes. However the conventional techniques for enhancing the directivity often lead to a significant increase in the size of the antenna. Consequently, the integration of directional antennas in small wireless device is limited. This difficulty is particularly critical for the frequency bands below one gigahertz if objects dimensions are limited to a few centimeters. However, the Internet of Things requires radiation control to reduce the electromagnetic pollution, which limits the acceptability of wireless communications, as well as to allow coexistence of ubiquitous systems. The radiation control is an important issue for future smart radio, with a limited impact on environment of the users. The recent state-of-the art in the field of miniature antennas shows new perspectives for the development of super-directivity. The increase of low directivity of electrically small-sized antennas is a modern motivation for super-directivity. Introduction of meta-materials is a positive perspective to mitigate the effects of coupling in compact antenna arrays. The use of compact parasite antennas can help a directional radiation. Moreover, recent research activities in the field of active antennas offer new opportunities for practical super-directivity implementation. Already, the state-of-the art shows concrete experiments of these issues. This project aims at improving the directivity of electrically small antennas. The consortium includes research teams from CEA-Leti and IETR working on antennas and propagation topics. CEA-Leti and IETR are equipped to address these issues (anechoic chamber facilities for UHF measurements, radio laboratories…). The scientific activity in the project is in line with recent achievements in the field of miniaturization of antennas in CEA-Leti and IETR. The project consortium also includes industrial partners Movea and Tagsys whom applications require directional antenna. Movea, a company selling hardware and software solutions for motion capture, will score the pointing applications where directivity of antenna is used to allow the user to designate the object to which the radio communication is established. Tagsys, a leader company in the passive RFID market for tracking of items, brings the need for radiation control necessitated by massive deployment of "tagged" items. The ambition of the project is preliminary theoretical work to establish principles and limitations in compact antenna directivity, the development of innovative miniature antenna concepts and a test campaign of antenna designs developed for Movea and Tagsys applications. The expected results are a scientific dissemination or filing of patents and an industrial dissemination through demonstration prefiguring industrial devices.