ABSTRACT

In this paper, a meander monopole antenna array based electromagnetic band gap (EBG) structure is proposed for MIMO applications. For this, two monopoles of a meander structure are printed on an FR4 substrate of 1.6 mm thickness and fed with 50Ω microstrip lines. The ground plane is defected with EBG Hilbert shaped inclusions of the 3rd order on the substrate back profile within a limited array size. This is achieved by having a negative refractive index (NRI) to reflect the surface waves totally away from the space filling between the antenna elements. Such property occurs only when the EBG defect operation is combined with the EBG slots. To realize the proposed design performance, a Finite Integral Technique (FIT) of CST Microwave Studio (CSTMWS) numerical analysis is invoked. Nevertheless, another numerical simulation based on Finite Element Method (FEM) based HFSS simulations is conducted to validate the regarded results. The proposed antenna design is fabricated to achieve excellent matching bandwidths, S₁₁<−10 dB, around 2.45 GHz. The proposed antenna radiation pattern is found in the side direction of the array with a gain of 2.1dBi at 2.45 GHz. The proposed antenna axial ratio (AR) is tested and found to be below 3 dB at 2.45 GHz; that makes the antenna subject for circularly polarized radiator. Such achievement is attributed to the effect the fractal structure additions. Finally, the maximum mutual coupling between the antenna elements within a distance of 0.16λ_o at 2.45 GHz is bellow −30 dB at the two frequency bands of interest.

摘要

在本文中，针对 MIMO 应用提出了一种基于曲折单极天线阵列的电磁带隙 (EBG) 结构。为此，在 1.6 mm 厚的 FR4 基板上印刷两个曲折结构的单极子，并用 50Ω 微带线馈电。在有限的阵列尺寸内，基板背面轮廓上的 EBG 希尔伯特形夹杂物使接地平面缺陷。这是通过具有负折射率 (NRI) 以将表面波完全反射远离天线元件之间的空间填充来实现的。只有当 EBG 缺陷操作与 EBG 时隙组合时，才会出现这种特性。为了实现所提出的设计性能，调用了 CST Microwave Studio (CSTMWS) 数值分析的有限积分技术 (FIT)。尽管如此，另一个基于有限元法 (FEM) 的基于 HFSS 模拟的数值模拟是为了验证所考虑的结果。所提出的天线设计是为了实现出色的匹配带宽而制造的，S ₁₁ <-10 dB，大约 2.45 GHz。建议的天线辐射方向图位于阵列的侧面，在 2.45 GHz 时增益为 2.1dBi。建议的天线轴比 (AR) 经测试发现在 2.45 GHz 时低于 3 dB；这使得天线受到圆极化辐射器的影响。这样的成就归功于分形结构添加的影响。_{最后，在 2.45 GHz 的 0.16λ o}距离内，天线元件之间的最大互耦合在两个感兴趣的频带下低于 -30 dB。