Application of elastic metamaterials/meta-structures in civil engineering: A review

Inspired by sonic engineering, locally resonant metamaterials have attracted much attention from researchers in civil engineering for their unique characteristics of stress wave attenuation and vibration control capacities. This paper presents a comprehensive review of the latest progress of locally resonant metamaterials and their potential applications in civil engineering for structure protection against dynamic loads. The concepts of metamaterials for stress wave attenuation are introduced first, followed by a comprehensive overview of the historical origins and development of metamaterials. Existing analytical approaches for metamaterials, including theoretical solutions, numerical simulations, and experimental examinations, are summarised. Commonly used meta-structures with internal or external resonators and their applications are reviewed and discussed. Research gaps and future outlooks are also identified and briefed

On the Antenna Position to Improve the Radiation Pattern Characterization

International audienceThe 3D characterization of radiating structures is a frequently encountered, and yet challenging, procedure. The theoretical sampling criterion often leads to prohibitive measurement duration, especially for antennas embedded on electrically large structures. However, the position of the antenna under test strongly influences the sampling requirements. By appropriately positioning the antenna with respect to the measurement system, it is possible to promote the low spatial frequency part of its spherical harmonic spectrum. We present a post-processing optimization algorithm enabling a systematic and accurate determination of the antenna best position from a given measurement dataset with no prior knowledge. This sooptimized position is exploited to improve the characterization of the antenna radiation pattern without resorting to any additional measurement sample. The proposed algorithm is validated for both near-field simulations and far-field measurements on various radiating structures, including an antenna embedded on a satellite model

Fast Antenna Characterization Improvement by Pattern Rotations

International audienc

Implementation of a VHF Spherical Near-Field Measurement Facility at CNES

International audienceThis paper presents last implementation of a complete near-field system including probe positioner upgrades to reach positioning repeatability and ergonomy, an optical alignment tool, a specific reference antenna and a post-processing tool