Four grounded coplanar waveguide (GCPW)-fed open-slot antennas conjoined into a cross shape with a central circular slot are presented for $4\times4$ fifth-generation (5G) multi-input multi-output (MIMO) operation in 3.3–4.2 GHz. The four conjoined slot antennas have a 1 mm low profile (about $0.01\lambda $ at 3.3 GHz) and a compact size of 42 mm $\times42$ mm (about $0.46\lambda \times 0.46\lambda $ at 3.3 GHz) to provide four wide operating bands (about 24% centered at 3.75 GHz) with antenna efficiency better than 40%. The conjoined circular slot leads to enhanced operating bandwidth of the four slot antennas and good decoupling thereof. Owing to the 1 mm low profile, the conjoined slot antennas are promising to be integrated within the dielectric back cover of the 5G terminal device, thereby decreasing the antennas’ volume inside the device. Details of the GCPW-fed conjoined slot antennas for 5G-MIMO operation are presented.

中文翻译：

---

由接地共面波导馈送的薄型宽带联合开槽天线，用于 4 W 4 5G MIMO 操作

四个接地共面波导 (GCPW) 馈电开槽天线连接成具有中心圆形缝隙的十字形状，用于 $4\times4$ 3.3–4.2 GHz 的第五代 (5G) 多输入多输出 (MIMO) 操作。四个联合缝隙天线具有 1 毫米的低剖面（约 $0.01\lambda $ 3.3 GHz) 和 42 毫米的紧凑尺寸 $\times42$ 毫米（约 $0.46\lambda \times 0.46\lambda $ 在 3.3 GHz）以​​提供四个宽工作频段（约 24% 以 3.75 GHz 为中心），天线效率优于 40%。连接的圆形缝隙导致四个缝隙天线的工作带宽增加并且其解耦良好。由于1毫米的薄型，联合缝隙天线有望集成在5G终端设备的介质后盖内，从而减少设备内部天线的体积。介绍了用于 5G-MIMO 操作的 GCPW 馈电联合缝隙天线的详细信息。