Anisotropic Microwave/Terahertz Metamaterials for Satellite Applications (ANISAT)

用于卫星应用的各向异性微波/太赫兹超材料 (ANISAT)

• 批准号: EP/S030301/1
• 负责人: William Whittow
• 金额: $ 67.59万
• 依托单位: Loughborough University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FS030301%2F1
• 关键词: Anisotropic; Microwave; Terahertz; Metamaterials; Satellite

There is growing interest in the UK space sector for communications, imaging and earth observation. Key to this is sending and receiving electromagnetic waves. To enable higher communication rates and get greater accuracy in imaging often higher frequencies are used. This project will develop new structures using microfabrication techniques to develop novel antennas and polarizers for satellites and the earth segment over frequencies from 28 GHz up to 1 THz. This frequency range overlaps and extends the currently used frequencies.ANISAT will address these five technical challenges:1) Designing anisotropic metamaterials;2) Exploiting these properties to design novel antennas, polarizers and RF devices;3) Developing novel methods of measuring these properties;4) Microfabricating heterogeneous anisotropic structures;5) Combining these elements into a series of demonstrators.The above five points are addressed in more detail below:i) When an electromagnetic wave moves through a material it is slowed down by the dielectric properties. If an artificial dielectric can be composed of small (compared to a wavelength) rectangular or elliptical inclusions, then this composite material will behave differently when the incident electromagnetic wave has different polarizations. This can be exploited to create circularly polarized antennas where the electric field traces a circle in time. This is an advantageous property for space communications. ii) Currently, dielectric measurements only consider the dielectric properties for one polarization and effectively assume the materials are isotropic. ANISAT will develop a novel measurement system using resonant metasurfaces that can measure the properties along all three axes. This will open a new degree of freedom for antenna and radiofrequency engineers. iii) These anisotropic artificial dielectrics will be used to design novel circularly polarized antennas. It is currently challenging to feed antennas to create circular polarization at frequencies above 50 GHz due to the small scale of the feed structure. High gain multi beam cavity antennas and polarizers will be designed at a range of frequencies up to 1 THz. iv) Initial anisotropic artificial dielectrics will be fabricated using 3D-printing. This provides a simple and readily exploitable fabrication process. However, the upper frequency range is limited to approximately 40 GHz by the size of the small-scale air/metal inclusions inside the composite. Above this frequency the inclusions approach the scale of a wavelength and they become resonant. To extend the frequency range, novel microfabrication processes in clean rooms will be developed and exploited. These include fully metallised SU8 photoresist polymers and/or silicon layers with a high dimensional accuracy of the scale of a few microns. v) The learning process will be multidisciplinary and iterative as each stage innovates further advances. The close geographical proximity of the two universities will be highly beneficial in this regard. The plan is to create laboratory demonstrators that can be showcased to industry. These provisionally include: a novel dielectric measurement system; a high gain circularly polarized antenna at Ka band (26 - 40 GHz); a circularly polarized Fabry-Perot antennas at frequencies up to 110 GHz; and linear to circular polarizers and beam splitters from 220 - 300 GHz and at a central frequency of 640 GHz.

人们对英国太空领域的通信、成像和地球观测越来越感兴趣。其关键是发送和接收电磁波。为了实现更高的通信速率并获得更高的成像精度，通常使用更高的频率。该项目将利用微加工技术开发新结构，为卫星和地球部分开发新型天线和偏振器，频率范围为 28 GHz 至 1 THz。该频率范围与当前使用的频率重叠并扩展。ANISAT将解决这五个技术挑战：1）设计各向异性超材料；2）利用这些特性来设计新型天线、偏振器和射频器件；3）开发测量这些特性的新方法；4）微加工异质各向异性结构；5）将这些元素组合成一系列演示器。以上五个 下面更详细地讨论了以下几点：i) 当电磁波穿过材料时，其介电特性会减慢速度。如果人造电介质可以由小的（与波长相比）矩形或椭圆形夹杂物组成，那么当入射电磁波具有不同偏振时，这种复合材料将表现出不同的行为。这可以用来创建圆极化天线，其中电场随时间追踪一个圆。这对于空间通信来说是一个有利的特性。 ii) 目前，介电测量仅考虑一种极化的介电特性，并有效地假设材料是各向同性的。 ANISAT 将开发一种使用共振超表面的新型测量系统，可以测量沿所有三个轴的特性。这将为天线和射频工程师带来新的自由度。 iii）这些各向异性人造电介质将用于设计新型圆极化天线。由于馈电结构的规模较小，目前在 50 GHz 以上的频率下馈电天线产生圆极化具有挑战性。高增益多波束腔天线和偏振器将设计在高达 1 THz 的频率范围内。 iv) 最初的各向异性人造电介质将使用 3D 打印来制造。这提供了简单且易于利用的制造工艺。然而，由于复合材料内部小尺寸空气/金属夹杂物的尺寸，上限频率范围被限制在大约 40 GHz。高于该频率，内含物接近波长尺度并产生共振。为了扩大频率范围，将开发和利用洁净室中的新型微加工工艺。其中包括全金属化的 SU8 光刻胶聚合物和/或硅层，具有几微米级的高尺寸精度。 v) 学习过程将是多学科和迭代的，每个阶段都会创新并进一步进步。两所大学地理位置接近，在这方面将非常有利。该计划是创建可以向业界展示的实验室演示器。这些暂时包括：一种新颖的介电测量系统； Ka 频段（26 - 40 GHz）高增益圆极化天线；频率高达 110 GHz 的圆极化法布里-珀罗天线；以及线性到圆偏振器和分束器，频率范围为 220 - 300 GHz，中心频率为 640 GHz。

项目成果

Wideband Radar-Cross-Section Reduction Using Parabolic Phased Metasurfaces

• DOI: 10.1109/lawp.2023.3250453
• 发表时间: 2023-07
• 期刊: IEEE Antennas and Wireless Propagation Letters
• 影响因子: 4.2
• 作者: M. Al-Nuaimi;W. Whittow;Guanhua Huang;Rui-Sen Chen;S. Wong

Hybrid cubic-chessboard metasurfaces for wideband angle-independent diffusive scattering and enhanced stealth.

混合立方棋盘超表面，用于宽带角度无关的扩散散射和增强的隐身性。

• DOI: 10.1364/oe.504200
• 发表时间: 2023
• 期刊: Optics express
• 影响因子: 3.8
• 作者: Al-Nuaimi MKT

Aperiodic Sunflower-Like Metasurface for Diffusive Scattering and RCS Reduction

• DOI: 10.1109/lawp.2020.2980906
• 发表时间: 2020-07-01
• 期刊: IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
• 影响因子: 4.2
• 作者: Al-Nuaimi, Mustafa K. Taher;Hong, Wei;Whittow, William G.
• 通讯作者: Whittow, William G.

Realization of Single-Layer Fourier Phased Metasurfaces for Wideband RCS Reduction

• DOI: 10.1109/lawp.2023.3235970
• 发表时间: 2023-05
• 期刊: IEEE Antennas and Wireless Propagation Letters
• 影响因子: 4.2
• 作者: M. Al-Nuaimi;Guanhua Huang;W. Whittow;Rui-Sen Chen;S. Wong

Design of Alvarez Beam Scanning Reflectarray With Inversely Proportional Focal Length

• DOI: 10.1109/lawp.2023.3243868
• 发表时间: 2023-06
• 期刊: IEEE Antennas and Wireless Propagation Letters
• 影响因子: 4.2
• 作者: M. Al-Nuaimi;Shiran Zhu;W. Whittow;Rui-Sen Chen;Guanhua Huang;Abdelhady Mahmoud