Enabling metamaterial solutions for antennas in wireless internet service provision (WISP)

在无线互联网服务提供（WISP）中，任何使天线更紧凑，低轮廓或多功能的努力都可能带来某些挑战，例如增加互耦合和复杂的天线架构，所有这些都不同程度地扩大了天线足迹，使设计复杂化，并提出制造挑战。尽管存在针对这些挑战的解决方案，但它们实际上可能会增加天线的尺寸，重量，复杂性和成本，并且它们通常采用ad-hoc或其他经验设计方法。另一个挑战是雷达罩对辐射参数的已知影响。这些结构的形状 ** 取决于特定应用的参数，如风阻和美观性，通常不会 ** 用于增强天线性能，尽管它们提供了一个有趣的机会。上述挑战需要在天线设计中利用新范例的更稳健的解决方案。电磁（EM）“超材料”（MTM）就是这样一种范例，它是一种周期性结构，旨在创造奇异的波传播特性-通常使用天然材料无法实现-并且可以进一步分为几种类型。其中包括EM带隙结构（EBG）和频率选择表面（FSS）的某些化身 **，前者通常用于调整导波应用（例如波导和TL）中的传播，后者通常用于设计自由空间中波的传输和反射响应。与KP Performance Inc.的合作（埃德蒙顿，AB -缩写KPPA）将研究 ** 设计紧凑型多功能分集天线，该天线结合了基于MTM的EBG** 技术的最新进展，以实现宽带和/或多频带操作，同时降低互耦。* * 本工作的第二个方面将分别使用基于MTM的FSS和EBG ** 研究天线罩和接地层的图案化，以实现更好的半功率波束宽度滚降、低旁瓣和改进的前后比。

In wireless internet service provision (WISP), any efforts to render antennas more compact, low-profile, or**multifunctional can bring certain challenges such as increased mutual coupling and complex antenna**architectures, all of which variously enlarge antenna footprints, complicate design, and present fabrication**challenges. Although solutions exist for these challenges, they may actually increase the size, weight,**complexity, and cost of the antenna, and they typically employ ad-hoc or otherwise empirical design methods.**A separate challenge is the known effect of radomes on radiation parameters. These structures, whose shapes**are dictated by application-specific parameters such as wind resistance and aesthetics, are not typically**exploited to enhance antenna properties, although they present an interesting opportunity to do so.**The above challenges demand a more robust solution drawing on new paradigms in antenna design. One such**paradigm is that of electromagnetic (EM) 'metamaterials' (MTMs), which are periodic structures engineered to**create exotic wave-propagation characteristics - often unavailable using natural materials - and which may be**further classified into several types. Among these are EM bandgap structures (EBGs) and certain incarnations**of frequency-selective surfaces (FSSs), where the former are typically used to tailor propagation in**guided-wave applications (e.g. waveguides and TLs) and the latter are typically used to engineer the**transmission and reflection response of waves in free space.**The proposed collaboration with KP Performance Inc. (Edmonton, AB -- abbreviated KPPA) will investigate**designing compact multifunction diversity antennas that incorporate recent advances in MTM-based EBG**technology to enable broadband and/or multi-band operation with reduced mutual coupling. A second aspect of**this work will examine patterning antenna radomes and ground planes using MTM-based FSSs and EBGs,**respectively, to effect better half-power beamwidth roll-off, low side-lobes, and improved front-to-back ratios.