In this paper, a novel design for a 5G base station (BS) antenna is proposed. The proposed antenna consists of two orthogonally polarized antennas. The two antennas are modified compact Vivaldi antennas operating in the two recommended 5G operating bands; 28 and 38 GHz with measured impedance bandwidth of 26.5–40 GHz. The orthogonality of the two antennas allows the use of two antennas on the same substrate within one enclosure to serve two sectors separately. So, instead of using two enclosures to serve two sectors, only one enclosure is required. The two elements may be part of two separate MIMO distributions. To minimize the isolation between the MIMO antennas elements with low complexity and low cost, the antenna elements have been distributed along the z-direction with half-wavelength spacing between elements including Electromagnetic band-gap (EBG) structure in between them. The simulation results have been shown that the measured mutual coupling between the array elements is improved from − 32 to − 45 dB at 28 GHz and from − 22 to − 59 at 38 GHz. The envelope correlation coefficient (ECC) is enhanced and the diversity gain (DG) is improved simultaneously. The suggested structure has been designed on CST Microwave Studio 2019. The two orthogonal antennas’ overall size approaches 34 mm × 55.8 mm × 0.203 mm³. The measured gain of the suggested design is enhanced from 10.4 to 12.8 dB at 28 GHz whereas a minor change is noticed at 38 GHz. The maximum simulated radiation efficiency approaches 96%. The antenna is fabricated and tested where good experimental results are noticed compared to the simulation results.

本文提出了一种5G基站（BS）天线的新颖设计。所提出的天线由两个正交极化天线组成。这两个天线是经过修改的紧凑型Vivaldi天线，它们在两个建议的5G工作频带中运行；28和38 GHz，测得的阻抗带宽为26.5–40 GHz。两个天线的正交性允许在一个外壳内的同一基板上使用两个天线，以分别为两个扇区提供服务。因此，无需使用两个机箱来为两个扇区提供服务，而是仅需要一个机箱。这两个元素可以是两个单独的MIMO分布的一部分。为了以低复杂度和低成本最小化MIMO天线元件之间的隔离，天线元件已沿z方向分布，元件之间具有半波长间隔，其中包括电磁带隙（EBG）结构。仿真结果表明，阵列元件之间的测量互耦在28 GHz时从− 32改善到– 45 dB，在38 GHz时从− 22改善到– 59。包络相关系数（ECC）增强，分集增益（DG）同时提高。建议的结构是在CST Microwave Studio 2019上设计的。两个正交天线的总体尺寸接近34 mm×55.8 mm×0.203 mm 包络相关系数（ECC）增强，分集增益（DG）同时提高。建议的结构是在CST Microwave Studio 2019上设计的。两个正交天线的总体尺寸接近34 mm×55.8 mm×0.203 mm 包络相关系数（ECC）增强，分集增益（DG）同时提高。建议的结构是在CST Microwave Studio 2019上设计的。两个正交天线的总体尺寸接近34 mm×55.8 mm×0.203 mm³。建议设计的测量增益在28 GHz时从10.4 dB增强到12.8 dB，而在38 GHz时发现很小的变化。最大模拟辐射效率接近96％。天线的制造和测试与仿真结果相比，可以发现良好的实验结果。