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

在无线互联网服务提供(WSAP)中，任何使天线更紧凑、更低调或 多功能可能会带来一定的挑战，如增加相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占地面积，使设计复杂化，并呈现出制造 挑战。虽然这些挑战已经有了解决方案，但它们实际上可能会增加尺寸、重量， 天线的复杂性和成本，他们通常采用特别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，它们的形状 由特定于应用的参数(如风阻和美观)决定，通常 被利用来增强天线性能，尽管它们提供了一个有趣的这样做的机会。 上述挑战需要一个更强大的解决方案，利用天线设计中的新范例。这样的一个 范例是电磁(EM)“超材料”(MTM)的范例，它是周期性的结构，被设计成 创造奇异的波传播特性--通常不能使用天然材料--这可能是 进一步分为几种类型。其中包括电磁带隙结构(EBG)和某些化身 频率选择表面(FSS)，其中频率选择表面通常用于在 导波应用(例如，波导和TL)和后者通常用于工程设计 波在自由空间中的传输和反射响应。 拟议中的与KP Performance Inc.(Edmonton，AB--缩写KPPA)的合作将调查 设计紧凑型多功能分集天线，结合基于MTM的EBG的最新进展 能够实现宽带和/或多频带操作并减少相互耦合的技术。的第二个方面 这项工作将使用基于MTM的FSS和EBG来检查形成图案的天线天线罩和接地面， 分别实现了更好的半功率波束宽度滚降、较低的旁瓣和改善的前后比。

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.