In this paper, a low profile compact 8-port multiband antenna with polarization diversity principle for automotive communication is proposed. The geometric of the proposed MIMO antenna is integrated with multiple stubs on substrate having a size of 0.94λ_g × 0.94λ_g. The proposed design resonates at multiple frequencies of 1.8, 2.4, 5.2, and 5.8 GHz, respectively for GSM, ISM bands and WLAN wireless services which covers the bandwidth of 2.8%, 5%, 5%, and 5.6%, respectively with S₁₁ ≤ −10 dB. Besides, the measured results provide a peak gain of 4.3, 3.1, 4.5, and 4.2 dBi at 1.8, 2.4, 5.2, and 5.8 GHz, omni directional radiation pattern with more than 80% of efficiency in all operating bands. The MIMO structure provides a good isolation of greater than 20 dB without decoupling structure, envelope correlation coefficient of ≤0.1, diversity gain of ≥9.99 dB, mean effective gain of <1 dB, total active reflection coefficient ≤−10 dB, channel capacity loss of ≤0.25 bits/s/Hz. Finally, the housing effect of MIMO antenna is analyzed in the vehicular environment which provides good performance for Vehicular to Intravehicular communication.

中文翻译：

---

汽车通信用8端口多业务四频MIMO天线设计与性能分析

本文提出了一种用于汽车通信的采用极化分集原理的薄型紧凑型 8 端口多频段天线。所提出的 MIMO 天线的几何结构是在尺寸为 0.94 λ _g  × 0.94 λ _g的基板上集成多个短截线。所提出的设计分别针对 GSM、ISM 频段和 WLAN 无线服务在 1.8、2.4、5.2 和 5.8 GHz 多个频率下谐振，覆盖的带宽分别为 S 11 的 2.8%、5%、5% 和5.6 _%  ≤−10 分贝。此外，测量结果显示，在 1.8、2.4、5.2 和 5.8 GHz 下的峰值增益分别为 4.3、3.1、4.5 和 4.2 dBi，全向辐射图，在所有工作频段中效率超过 80%。MIMO结构无需解耦结构即可提供大于20dB的良好隔离度，包络相关系数≤0.1，分集增益≥9.99dB，平均有效增益<1dB，总有源反射系数≤−10dB，信道容量损耗≤0.25 位/秒/赫兹。最后，分析了车载环境中MIMO天线的外壳效应，为车内通信提供了良好的性能。