A Class of Focusing Waves with Controllable Spatial Extension and Directivity

International audienceSlepian's concentration operator is applied in order to define a set of focusing waves with finite angular spread and the highest spatial focusing possible. These waves can be used as building blocks for the definition of any wave that requires to ensure both angular and spatial resolution, as an optimal trade-off within the bounds imposed by the uncertainty principle. Applications of these results can be expected in the form of focusing waves yielding higher energy efficiency for antenna characterization, EMC radiative-immunity tests, electronic warfare, as well as spatially-resolved beamforming

Analysis of Time-Reversal-Based Propagation for Spatial focusing and Multiplexing

4 pagesInternational audienceTime-Reversal (TR) technique is well-known for itsability of focusing waves. A common claim, based on this focusing ability, supports that TR technique may allow spatial multiplexing and secure transmissions. In the present paper, measurements campaigns were performed in a reverberation chamber and in a standard office to assess the viability of TR technique. It is shown that the results obtained do not support the common claim, especially in standard indoor environment where the focusing ability is strongly degraded