In this article, a highly directive slot antenna design using a parallel incident magnetic metamaterial (MTM) structure has been presented. A split ring resonator (SRR) structure having mu near-zero and epsilon very large with low impedance behavior is employed to enhance the directivity of the antenna. In the proposed optimized design, four-MTM slabs with an array of $2×2$ SRR unit cell have been placed perpendicularly over the slot antenna to enhance the directivity. The thickness of utilized MTM slab in the vertical direction is under the optimal condition, which is highly desired to obtain better improvement in directivity. In spite of directivity enhancement of about 6 dB, antenna miniaturization of 11.4% is also obtained due to the loading effect of the MTM slab. The proposed directivity enhancement approach of the slot antenna is established by simulation and verified by measurements. It is perceived from both measured and simulated results that over the whole working band, a significant directivity enhancement is sustained along with reduced backward radiation compared to the unloaded slot.

中文翻译：

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优化条件下超材料结构的高指向性缝隙天线设计

在本文中，介绍了一种使用平行入射磁性超材料 (MTM) 结构的高度定向缝隙天线设计。裂环谐振器 (SRR) 结构具有接近零的 μ 和非常大的ε，具有低阻抗行为，用于增强天线的方向性。在建议的优化设计中，具有一系列$2一种-2$SRR 单元已垂直放置在缝隙天线上方以增强方向性。所使用的MTM板在垂直方向的厚度处于最佳条件下，非常需要获得更好的方向性改善。尽管方向性增强了约 6 dB，但由于 MTM 板的加载效应，天线也实现了 11.4% 的小型化。提出的缝隙天线方向性增强方法是通过仿真建立并通过测量验证的。从测量结果和模拟结果都可以看出，在整个工作频段上，与空载槽相比，方向性显着增强，反向辐射减少。