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、更低姿态或更多功能的努力都会带来一定的挑战，例如增加相互耦合和复杂的天线架构，所有这些都会增加天线占地面积，使设计复杂化，并提出制造挑战。尽管针对这些挑战存在解决方案，但它们实际上可能会增加天线的尺寸、重量、复杂性和成本，并且它们通常采用特设或其他经验设计方法。另一个挑战是已知的天线罩对辐射参数的影响。这些结构的形状由特定应用参数（如抗风性能和美观性）决定，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。上述挑战需要一个基于天线设计新范式的更强大的解决方案。电磁（EM）“超材料”（mtm）就是这样一种范例，它是一种周期性结构，用于创造奇异的波传播特性——通常使用天然材料是不可用的——并且可以进一步分为几种类型。其中包括电磁带隙结构（EBGs）和某些频率选择表面（fss），前者通常用于定制传播导波应用（例如波导和TLs），后者通常用于设计波在自由空间中的传输和反射响应。与KP Performance Inc.（埃德蒙顿，AB -简称KPPA）的拟议合作将研究设计紧凑型多功能分集天线，该天线将结合基于mtm的ebg技术的最新进展，以减少互耦，实现宽带和/或多频段操作。这项工作的第二个方面将分别使用基于mtm的fss和EBGs对天线天线罩和地平面进行图图化，以实现更好的半功率波束宽度滚降、低侧瓣和改进的前后比。

In wireless internet service provision (WISP), any efforts to render antennas more compact, low-profile, ormultifunctional can bring certain challenges such as increased mutual coupling and complex antennaarchitectures, all of which variously enlarge antenna footprints, complicate design, and present fabricationchallenges. 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 shapesare dictated by application-specific parameters such as wind resistance and aesthetics, are not typicallyexploited 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 suchparadigm is that of electromagnetic (EM) 'metamaterials' (MTMs), which are periodic structures engineered tocreate exotic wave-propagation characteristics - often unavailable using natural materials - and which may befurther classified into several types. Among these are EM bandgap structures (EBGs) and certain incarnationsof frequency-selective surfaces (FSSs), where the former are typically used to tailor propagation inguided-wave applications (e.g. waveguides and TLs) and the latter are typically used to engineer thetransmission and reflection response of waves in free space.The proposed collaboration with KP Performance Inc. (Edmonton, AB -- abbreviated KPPA) will investigatedesigning compact multifunction diversity antennas that incorporate recent advances in MTM-based EBGtechnology to enable broadband and/or multi-band operation with reduced mutual coupling. A second aspect ofthis 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.