In this letter, a multiple-input–multiple-output (MIMO) antenna with wideband performance for 5G smartphones is presented. First, a planar inverted-F antenna (PIFA) with an inverted-T-shaped open-slot is introduced. The proposed PIFA operates with a wide bandwidth of 78% due to the multimode technology. Then, two such PIFAs are attempted to be merged as a PIFA-pair, constituting a 2 × 2 sub-MIMO antenna with a similar bandwidth as the PIFA-element. Additionally, the isolation between two PIFA-elements in a PIFA-pair is higher than 10 dB across the broadband. Finally, a 4 × 4 MIMO antenna, which is composed of two PIFA-pairs, is demonstrated to cover the 5G NR frequency bands: n77/n78/n79 and LTE band 46. The simulated and measured results are included for illustrating the performance of the proposed MIMO antenna.

中文翻译：

---

适用于5G智能手机的基于宽带PIFA对的MIMO天线

在这封信中，提出了具有5G智能手机宽带性能的多输入多输出（MIMO）天线。首先，介绍了具有倒T形开槽的平面倒F天线（PIFA）。由于采用了多模技术，因此建议的PIFA可以在78％的宽带宽下运行。然后，尝试将两个这样的PIFA合并为一个PIFA对，从而构成一个带宽与PIFA元素相似的2×2子MIMO天线。此外，整个宽带中，PIFA对中两个PIFA元素之间的隔离度高于10 dB。最后，演示了由两个PIFA对组成的4×4 MIMO天线，覆盖了5G NR频段：n77 / n78 / n79和LTE频段46。仿真和测量结果包括在内，以说明其性能。提出的MIMO天线。