A low-profile differentially fed dual-polarized antenna with high gain and isolation is proposed for fifth-generation (5G) microcell communications. By introducing two pairs of symmetrical meandering conductors to connect both ends of the radiating cross slots, a compact-size antenna with wide bandwidth can be achieved. By further adopting an artificial magnetic conductor-backed (AMC) reflector that is arranged below the radiating patches with a distance of 6 mm, the antenna profile can be reduced from $0.25\lambda _{c}$ to $0.13\lambda _{c}$ (where $\lambda _{c}$ is the free-space wavelength at the center frequency), while both the gain and frequency bandwidth are also enhanced. Furthermore, owing to the orthogonal differentially fed structure, the antenna element displays a high port isolation of 37 dB. Finally, by meticulously designing the feeding network, much narrower beamwidth can be yielded, and hence, the unidirectional gain is further improved. The measured results show that a lower-frequency bandwidth of 13.5% (3.26–3.73 GHz) with a gain of 15.7 ± 0.1 dBi and upper-frequency bandwidth of 7.6% (4.68–5.05 GHz) with 15.55 ± 0.05 dBi gain can be obtained by the proposed antenna array. In addition, port isolation better than 28 dB and stable radiation patterns can be achieved. With the aforementioned characteristics, the proposed antenna is a good candidate for future 5G microcell communications.

中文翻译：

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用于 5G 微蜂窝通信的具有高增益和隔离度的薄型差分馈电双极化天线

为第五代 (5G) 微蜂窝通信提出了一种具有高增益和隔离度的低剖面差分馈电双极化天线。通过引入两对对称的曲折导体连接辐射交叉缝隙的两端，可以实现宽带宽的紧凑尺寸天线。通过在辐射贴片下方进一步采用 AMC 反射器，距离为 6 mm，天线剖面可以从 $0.25\lambda _{c}$ 至 $0.13\lambda _{c}$ （在哪里 $\lambda _{c}$ 是中心频率处的自由空间波长），同时增益和频率带宽也得到了增强。此外，由于正交差分馈电结构，天线元件显示出 37 dB 的高端口隔离度。最后，通过精心设计馈电网络，可以产生更窄的波束宽度，从而进一步提高单向增益。实测结果表明，可以获得13.5%（3.26-3.73 GHz）的低频带宽，增益为15.7±0.1 dBi，高频带宽为7.6%（4.68-5.05 GHz），增益为15.55±0.05 dBi通过建议的天线阵列。此外，端口隔离度优于 28 dB，可实现稳定的辐射模式。凭借上述特性，所提出的天线是未来 5G 微蜂窝通信的良好候选者。