{"id":419,"date":"2019-10-09T10:41:49","date_gmt":"2019-10-09T10:41:49","guid":{"rendered":"http:\/\/clem.dii.unisi.it\/~aelab\/wordpress\/?page_id=419"},"modified":"2020-03-04T17:40:09","modified_gmt":"2020-03-04T17:40:09","slug":"metamaterial-lenses","status":"publish","type":"page","link":"https:\/\/clem.dii.unisi.it\/~aelab\/wordpress\/index.php\/metamaterial-lenses\/","title":{"rendered":"Metamaterial antennas"},"content":{"rendered":"\n<div class=\"wp-block-media-text alignwide\"><figure class=\"wp-block-media-text__media\"><img loading=\"lazy\" decoding=\"async\" width=\"435\" height=\"585\" src=\"http:\/\/clem.dii.unisi.it\/~aelab\/wordpress\/wp-content\/uploads\/lenses-2.png\" alt=\"\" class=\"wp-image-423\" srcset=\"https:\/\/clem.dii.unisi.it\/~aelab\/wordpress\/wp-content\/uploads\/lenses-2.png 435w, https:\/\/clem.dii.unisi.it\/~aelab\/wordpress\/wp-content\/uploads\/lenses-2-223x300.png 223w\" sizes=\"auto, (max-width: 435px) 100vw, 435px\" \/><\/figure><div class=\"wp-block-media-text__content\">\n<p> At millimeter and sub-millimeter wavelengths lens-antennas are a valuable alternative to reflect-antennas, since at these working frequencies they come in more compact configurations. As for reflect-antennas, lens-antennas are able to increase the gain of a primary feed antenna positioned in a focal point or, reciprocally, to focus parallel rays, describing an incident plane wave, in a specific point. The law describing the behaviour of reflect- and lens- antennas is the Snell\u2019s law for reflection and refraction, respectively. Moreover, both lens- and reflect-antennas allow the possibility of reshaping the amplitude and phase distribution of the electromagnetic field at the aperture and, thus, the radiated pattern.  However, the possibility of manufacturing lenses with a spatially variable refractive index adds more degrees of freedom in the design. In particular, dielectric metamaterials (DMTM) comprised of resonating or sub-resonating elements can form low-loss graded index (GRIN) media. These media can be easily fabricated by 3D printing, enabling a significant cost-reduction without decreasing performances.<\/p>\n\n\n\n<p> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;  <\/p>\n\n\n\n<p class=\"has-small-font-size\"> Fig. 1 \u2013 Lens Antenna transforming spherical wave fronts in planar ones (plane wave), allowing the enhancement of radiation parameters (high gain and low Side-Lobe-Level)*<\/p>\n\n\n\n<p><\/p>\n<\/div><\/div>\n\n\n\n<p style=\"text-align:left\"><\/p>\n\n\n\n<p class=\"has-small-font-size\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>At millimeter and sub-millimeter wavelengths lens-antennas are a valuable alternative to reflect-antennas, since at these working frequencies they come in more compact configurations. As for reflect-antennas, lens-antennas are able to increase the gain of a primary feed antenna positioned in a focal point or, reciprocally, to focus parallel rays, describing an incident plane wave, in [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-419","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/clem.dii.unisi.it\/~aelab\/wordpress\/index.php\/wp-json\/wp\/v2\/pages\/419","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/clem.dii.unisi.it\/~aelab\/wordpress\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/clem.dii.unisi.it\/~aelab\/wordpress\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/clem.dii.unisi.it\/~aelab\/wordpress\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/clem.dii.unisi.it\/~aelab\/wordpress\/index.php\/wp-json\/wp\/v2\/comments?post=419"}],"version-history":[{"count":5,"href":"https:\/\/clem.dii.unisi.it\/~aelab\/wordpress\/index.php\/wp-json\/wp\/v2\/pages\/419\/revisions"}],"predecessor-version":[{"id":525,"href":"https:\/\/clem.dii.unisi.it\/~aelab\/wordpress\/index.php\/wp-json\/wp\/v2\/pages\/419\/revisions\/525"}],"wp:attachment":[{"href":"https:\/\/clem.dii.unisi.it\/~aelab\/wordpress\/index.php\/wp-json\/wp\/v2\/media?parent=419"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}