{"id":52470,"date":"2022-05-09T15:36:50","date_gmt":"2022-05-09T13:36:50","guid":{"rendered":"https:\/\/www.iemn.fr\/?p=52470"},"modified":"2022-11-24T15:14:53","modified_gmt":"2022-11-24T13:14:53","slug":"these-de-ali-mourad-codage-par-metasurfaces-pour-la-manipulation-de-faisceaux","status":"publish","type":"post","link":"https:\/\/www.iemn.fr\/en\/actualites\/these-de-ali-mourad-codage-par-metasurfaces-pour-la-manipulation-de-faisceaux.html","title":{"rendered":"Th\u00e8se de Ali MOURAD : \u00ab\u00a0Codage par m\u00e9tasurfaces pour la manipulation de faisceaux\u00a0\u00bb"},"content":{"rendered":"<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-wqkogm-3542ef5cb324c49a0fcc754fb4e858cf\">\n.flex_column.av-wqkogm-3542ef5cb324c49a0fcc754fb4e858cf{\nborder-radius:0px 0px 0px 0px;\npadding:0px 0px 0px 0px;\n}\n<\/style>\n<div  class='flex_column av-wqkogm-3542ef5cb324c49a0fcc754fb4e858cf av_one_full  avia-builder-el-0  avia-builder-el-no-sibling  first flex_column_div av-zero-column-padding'     ><section  class='av_textblock_section av-l2yrkfr1-7e606543509b5772dc0a6710f1f0a455'   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><h3 style=\"text-align: center;\">Th\u00e8se de Ali MOURAD<\/h3>\n<h4 style=\"text-align: center;\">\u00ab\u00a0Codage par m\u00e9tasurfaces pour la manipulation de faisceaux\u00a0\u00bb<\/h4>\n<blockquote>\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-qlkkpi-9b02ae2b280ed39729853de6770a0c79\">\n.av_font_icon.av-qlkkpi-9b02ae2b280ed39729853de6770a0c79 .av-icon-char{\nfont-size:30px;\nline-height:30px;\n}\n<\/style>\n<span  class='av_font_icon av-qlkkpi-9b02ae2b280ed39729853de6770a0c79 avia_animate_when_visible av-icon-style- avia-icon-pos-left av-no-color avia-icon-animate'><span class='av-icon-char' aria-hidden='true' data-av_icon='\ue8c9' data-av_iconfont='entypo-fontello' ><\/span><\/span>\n<p>Soutenance le 30\/06\/2022 \u00e0 10h30<br \/>\nAmphitheater of the IEMN - Central Laboratory - Villeneuve d'Ascq<\/p>\n<\/blockquote>\n<h4>Jury :<\/h4>\n<p>Genevieve MAZ\u00c9-MERCEUR, Directrice de recherche, CEA-CESTA, Rapporteur<br \/>\nAurelian CRUNTEANU, Directeur de recherche CNRS, XLIM, Rapporteur<br \/>\nPhilippe POULIGUEN, Responsable AID, DGA, Examinateur<br \/>\nMarc LE ROY, MCF, LABSTICC, Universit\u00e9 de Bretagne Occidentale, Examinateur<br \/>\nAbdelkrim TALBI, Professeur, IEMN, \u00c9cole Centrale de Lille, Examinateur<br \/>\n\u00c9ric LHEURETTE, Professeur, IEMN, Universit\u00e9 de Lille, Directeur<br \/>\nLudovic BURGNIES, MCF, IEMN, Universit\u00e9 du Littoral C\u00f4te d\u2019Opale, Co-encadrant<\/p>\n<h4>Summary:<\/h4>\n<p>Dans cette th\u00e8se, nous d\u00e9veloppons une m\u00e9thode pour l\u2019impl\u00e9mentation de metasurfaces \u00e0 forte diffusion \u00e0 l\u2019aide de m\u00e9tasurfaces \u00e0 codage al\u00e9atoire 1-bit. De telles metasurfaces permettent de r\u00e9duire la Surface Equivalente Radar (SER) dans une large bande de fr\u00e9quences sans produire de signature dans l\u2019infrarouge. Cinq m\u00e9tasurfaces \u00e0 codage par diffusion 1-bit compos\u00e9es d\u2019\u00e9l\u00e9ments binaires 8\u00d78 \u00e0 faible effet de couplage ont \u00e9t\u00e9 con\u00e7ues, fabriqu\u00e9es et caract\u00e9ris\u00e9es. Pour obtenir les meilleures performances des m\u00e9tasurfaces, une m\u00e9thode efficace de minimisation appel\u00e9e \u201cPattern Search\u201d est utilis\u00e9e avec la formule de r\u00e9duction de SER (RCSR) pour obtenir une disposition optimale des \u00e9l\u00e9ments distribu\u00e9s de fa\u00e7on al\u00e9atoire dans une m\u00e9tasurface \u00e0 codage. La simulation des m\u00e9tasurfaces de dimension r\u00e9elle avec le logiciel CST Microwave Studio et les r\u00e9sultats de mesure montrent une r\u00e9duction de SER, dans le cas d\u2019une incidence normale polaris\u00e9e lin\u00e9airement, en dessous de -10 dB par rapport \u00e0 la SER maximale d\u2019un plan m\u00e9tallique parfait (PEC) de la m\u00eame taille sur une large bande de fr\u00e9quence de 28 \u00e0 40 GHz, et avec une faible sensibilit\u00e9 \u00e0 l\u2019angle d\u2019azimut de l\u2019onde incidente.<\/p>\n<h4>Abstract:<\/h4>\n<p>In this thesis, a method for the implementation of highly scattering metasurfaces using 1-bit random coding metasurfaces is introduced. Such metasurfaces allow to reduce the radar cross section (RCS) in a broad frequency band without producing a signature in the infrared region. Five thin and broadband 1-bit diffusion coding metasurfaces composed of 8 \u00d7 8 binary elements with low coupling effect are designed, fabricated and characterized. For achieving the best performance of the metasurfaces, an efficient method of minimization called \u201cPattern Search\u201d is utilized together with the RCS reduction (RCSR) formula in order to achieve an optimal arrangement of randomly distributed elements in a coding metasurface. Simulation of the complete metasurfaces with the CST Microwave Studio software and measurement results show a RCS reduction, in the event of a normal linearly polarized incidence, below -10 dB when compared to the maximum of RCS for a perfect electric conductor (PEC) with the same size over a broad frequency band from 28 to 40 GHz, and with low sensitivity to the azimuth angle of the incident wave.<\/p>\n<\/div><\/section><\/div>","protected":false},"excerpt":{"rendered":"","protected":false},"author":2,"featured_media":52473,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8,65,316],"tags":[],"class_list":["post-52470","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-actualites","category-agenda","category-theses-2022"],"_links":{"self":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts\/52470","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/comments?post=52470"}],"version-history":[{"count":0,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts\/52470\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/media\/52473"}],"wp:attachment":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/media?parent=52470"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/categories?post=52470"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/tags?post=52470"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}