Two configurations of a modified feather-shaped antenna element are proposed for super wideband (SWB) multiple-input multiple-output (MIMO) applications. The antenna element geometry comprises of a circular slot-loaded feather-shaped radiator and rectangular notch-loaded quarter elliptical coplanar waveguide ground plane. An operating bandwidth of 4.4–51.5 GHz with inter-port isolation, S21 ≥ 15 dB for spatial diversity configuration, and 3.8–51.5 GHz with S21 ≥ 15 dB in pattern diversity configuration are achieved. The footprints of the antenna configurations are 17 × 33 and 31 × 31 mm2. Both configurations exhibited an envelope correlation coefficient of <−20 dB. The proposed MIMO configurations are fabricated and experimentally validated. The designed antenna configurations are SWB and compact.

中文翻译：

---

羽状超宽带MIMO天线

为超宽带 (SWB) 多输入多输出 (MIMO) 应用提出了两种改进的羽毛形天线元件配置。天线元件的几何结构包括圆形槽加载的羽毛状辐射器和矩形槽口加载的四分之一椭圆共面波导接地平面。4.4–51.5 GHz 的工作带宽，具有端口间隔离，小号21≥ 15 dB 用于空间分集配置，3.8–51.5 GHz小号21在模式分集配置中实现了 ≥ 15 dB。天线配置的占位面积为 17 × 33 和 31 × 31 mm2. 两种配置都表现出 <-20 dB 的包络相关系数。所提出的 MIMO 配置经过制造和实验验证。设计的天线配置为 SWB 且紧凑。