High‑permittivity ceramics enabled highly homogeneous zero‑index metamaterials for high‑directivity antennas and beyond  

作　　者：Yueyang Liu Tian Dong Xu Qin Weijia Luo Ning Leng Yujing He Yong Yuan Ming Bai Jingbo Sun Ji Zhou Yue Li Yang Li 

机构地区：[1]State Key Laboratory of Precision Measurement Technology and Instruments,Department of Precision Instrument,Tsinghua University,Beijing 100084,China [2]Department of Electronic Engineering,Tsinghua University,Beijing 100084,China [3]State Key Laboratory of New Ceramics and Fine Processing,School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China [4]The School of Electronic and Information Engineering,Beihang University,Beijing 100191,China

出　　处：《eLight》2024年第1期262-271,共10页e光学(英文)

基　　金：supported by the National Key Research and Development Program of China(2021YFB2801600);National Natural Science Foundation of China(62075114),Beijing Natural Science Foundation(4212050,Z220008);Zhuhai Industry University Research Collaboration Project(ZH-22017001210108PWC).

摘　　要：Zero-index metamaterials(ZIMs)can support uniform electromagnetic field distributions at any frequency,but their applications are hampered by the ZIM’s homogenization level—only 3 unit cells per free-space wavelength,which is fundamentally limited by the low-permittivity inclusions(εr≈12)and background matrix(εr≈1).Here,by filling high-permittivity SrTiO3 ceramic(εr≈294)pillars in BaTiO3(εr≈25)background matrix,we demonstrate a highly homogeneous microwave ZIM with an over threefold increase in the homogenization level.Leveraging such a ZIM,we achieve not only an antenna,approaching the fundamental limit in the directivity with outstanding scalability,but also a concave lens with a focal length of as short as 1λ0.Our highly homogeneous ZIM has profound implications in ceramics,ZIM-based waveguides and cavities,free-space wavefront manipulation,and microwave quantum optics,and opens up enormous possibilities in wireless communications,remote sensing,global positioning satellites,etc.

关 键 词：Zero-refractive index METAMATERIALS Antenna 

分 类 号：TQ1[化学工程]