FLEXIBLE SUBSTRATE CHARACTERIZATION FOR INNOVATIVE SMALL ANTENNA - BELOCOPA PROJECT

International audience
The search of a plane wreck just crashed can be extremely delicate. Since the flight crash AF447 Rio-Paris, this problem has become serious in the air security. The idea to design a removable and visible buoy is a part of the recommendations from the French authority BEA responsible for safety investigations into accidents or incidents in civil aviation. The BELOCOPA [1, 2] project is done in this context. Three companies and two laboratories of the PACA French region work on this project. The objectives are to localize the buoy with the GPS signal, to emit the security distress signal and to transmit the data, all of this in a reduced volume of an autonomous beacon ejected at the moment of the crash. The theoretical and experimental study of the deployable antenna of the beacon is the main task coming within the competency of the Fresnel Institute (figure 1). A simple innovative antenna [3, 4] transmitting at several frequencies, operating especially at the GPS, the security distress signal and data transmission frequencies is designed. The electromagnetic characterization of materials in terms of permittivity and permeability [5] included in the composition of the beacon is the other main task to master the different link budgets in the transmissions between the beacon and the different air and sea and/or satellite resources. The characterization of a flexible substrate is a delicate operation because techniques perfectly adapted to the studied frequencies do not exist. At the Fresnel Institute, we need to extrapolate the well-handled techniques on solids to the flexible substrates. We have developed a new experimental technique (figure 2) in this aim to be able to characterize every materials used in the antenna part of the buoy (flexible substrate and inflatable radome). The presented results show the progress status of the innovative techniques for the BELOCOPA project in the conception of flexible antennas, multi-frequency antennas and knowledge of dielectric