In this paper, a compact 4-port band-notched multi-input-multi-output (MIMO) antenna with asymmetric coplanar strip (ACS) feed is presented for ultra-wide band (UWB) applications. The MIMO antenna is comprised of four semi-elliptical radiators with ACS feed for UWB applications and it is printed on inexpensive FR4 substrate of size 48 × 52 mm2 with ɛr = 4.4 and 1.6 mm height. The impedance characteristics of the suggested MIMO antenna ranges from 2.7 to 11 GHz with a band-notched behavior from 3 to 4 GHz to reduce the interception with WiMAX applications, and the isolation level over the achieved band is more than 20 dB between any two adjacent elements. Moreover, the radiation pattern of the proposed UWB antenna is almost omnidirectional with an average realized gain of 3.5 dBi over the entire achieved frequency band. The proposed ACS-fed antenna is confirmed by fabricating and measuring it's impedance and radiation characteristics. Finally, good consistency between simulation and measured outcomes is obtained confirming the validity of the MIMO antenna for real-life UWB wireless systems.

中文翻译：

---

用于 UWB 通信的具有带陷特征的高隔离 4 元件 ACS 馈电 MIMO 天线

在本文中，提出了一种用于超宽带 (UWB) 应用的具有非对称共面带 (ACS) 馈电的紧凑型 4 端口带槽多输入多输出 (MIMO) 天线。MIMO 天线由四个带 ACS 馈电的半椭圆辐射器组成，适用于 UWB 应用，并且印刷在尺寸为 48 × 52 mm 的廉价 FR4 基板上2和εr= 4.4 和 1.6 毫米高度。建议的 MIMO 天线的阻抗特性范围为 2.7 至 11 GHz，带陷特性为 3 至 4 GHz，以减少与 WiMAX 应用的截获，并且在所实现的频带上，任何两个相邻的隔离水平超过 20 dB元素。此外，所提出的 UWB 天线的辐射方向图几乎是全向的，在整个实现的频带上平均实现增益为 3.5 dBi。所提出的 ACS 馈电天线通过制造和测量其阻抗和辐射特性得到证实。最后，仿真结果与测量结果之间的良好一致性证实了 MIMO 天线在实际 UWB 无线系统中的有效性。