Development of new planar retarding surfaces for mm- and sub-mm wave applications

这是一种基于亚波长周期或准周期结构的平面金属网状延迟表面，它可以选择性地延迟微波(GHz)至亚毫米波(THz)区域的电磁辐射。表面充当人造双折射材料，以提供出色的偏振选择性，或作为透镜的空间变化的人造介电材料。由于它们紧凑、坚固、轻便，并表现出低损耗和高性能可预测性的有利特性，这些表面具有改变各种仪器的基本设计的潜力，这些仪器工作在微波到频谱的亚毫米波区。例如：电信系统、雷达系统、毫米波成像、卫星通信、地球观测和空间科学、工业无损测试和检查、生物调查、遥感、安全、实验室测试设施和天文仪器。新表面是频率选择表面(FSS)中使用的金属栅格技术的更复杂实现。与FSS一样，它们可以通过在塑料衬底上蒸发铜来制造，其几何结构由标准光刻技术定义。因此，制造成本很低。创新是：i)设计大规模的空间不变的几何各向异性，以提供不同的正交偏振态的行为；ii)设计空间可变的几何--在有效折射率中产生梯度。这些创新基于：i)对电磁波与集总复阻抗元素相互作用的物理学有深刻的物理理解；ii)使用标准软件(HFSS)提取集总元素特征--通常是根据经验推断的；iii)准确地模拟具有大量元素的复杂结构的能力-超出了当前在PC上运行的商业代码的能力。RTG小组的专业知识、处理和测试设施将极大地促进研究计划的成功完成。这项赠款申请的成功将是将大量知识从射电天文学领域转移到解决更广泛技术领域的实际需要方面的关键一步。

This proposal is to design planar metal mesh retarding surfaces, based on sub-wavelength periodic or quasi-periodic structures, which selectively retard EM radiation in the microwave (GHz) to sub-mm wave (THz) regions of the spectrum. The surfaces act as artificial birefringent materials, to provide excellent polarization selectivity, or spatially varying artificial dielectrics to act as lenses. Because they are compact, robust, lightweight and exhibit favourable properties of low-loss and high predictability of performance these surfaces have the potential of altering the basic designs of a variety of instruments operating in the microwave to sub-mm wave regions of the spectrum. Examples include: telecommunications systems, radar systems, millimetre wave imaging, satellite communications, Earth observations and space science, industrial non-destructive testing and inspection, biological investigation, remote sensing, security, laboratory testing facilities and astronomical instrumentation.The new surfaces are more complex realizations of the metal grid techniques used in frequency selective surfaces (FSS). As with FSS they can be made by means of copper evaporation onto plastic substrates with the geometrical structures defined by standard photolithographic techniques. The manufacturing costs are therefore low. The innovations are: i) the design of large-scale spatially-invariant geometrical anisotropies to provide different behaviour for orthogonal polarization states; ii) the design of spatially-variant geometries-resulting in gradients in effective refractive. These innovations are based on: i) a deep physical understanding of the physics of the interaction of EM waves with lumped complex impedance elements; ii) the use of standard software (HFSS) to extract the lumped element characteristics-normally inferred empirically; iii) the ability accurately to model complex structures with large numbers of elements-beyond the capabilities of current commercial codes running on PCs.The PI works within the Manchester Radio Technology Group within the Jodrell Bank Centre for Astrophysics. The expertise, the processing and the testing facilities of the RTG group will greatly facilitate the successful completion of the research programme. The success of this grant application will be a key step in transferring considerable knowledge from the area of radioastronomy to solve real needs in the broader technological arena.