A Compact Tri-Port MIMO Antenna With High Isolation for Broadside and Conical Radiation

作     者：Gao, Guo-Ping Bai, Jin-Ming Jin, Li-Jun Guo, Wen-Di Ma, Ge Hu, Bin 

作者机构：Lanzhou University Gansu Provincial Key Laboratory of Wearable Computing School of Information Science and Engineering Lanzhou730000 China 

出 版 物：《IEEE Internet of Things Journal》 (IEEE Internet Things J.)

年 卷 期：2025年第12卷第9期

页      面：12219-12225页

核心收录：

学科分类：0831[工学-生物医学工程（可授工学、理学、医学学位）] 0810[工学-信息与通信工程] 0808[工学-电气工程] 0817[工学-化学工程与技术] 08[工学] 0804[工学-仪器科学与技术] 

基　　金：This work was supported in part by the Natural Science Foundation of Gansu Province under Grant 22JR5RA491 in part by the National Natural Science Foundation of China under Grant 62227807 and Grant 62076113 and in part by the National Key Research and Development Program of China under Grant 2019YFA0706200 

主　　题：Wearable antennas 

摘      要：Wearable Internet of Things (IoT) devices are widely used in many fields. Such as smart bracelets for health, smart watches for sports, smart safety helmets for industry, and so on. These devices make life easier and more efficient. Multiple-input–multiple-output (MIMO) antenna technology improves data transmission rates and communication reliability by using multiple antennas in a device, so as to meet the demand for real-time data transmission and multidevice connectivity in the IoT. A compact tri-port MIMO antenna with high isolation suitable for wearable applications is proposed. The antenna is designed to work in the frequency band of 2.45 GHz industrial, scientific, and medical (ISM). The antenna has two layers and three ports with low profile suitable for wearable applications. The upper layer is a circular patch with four shorting pins, which excites the TM01 mode with a conical radiation pattern. The lower layer is a circular patch inlaid in an annular patch, which respectively excite the TM11 mode and the TM31 mode with a broadside radiation pattern. To achieve high isolation, characteristic mode analysis (CMA) was conducted on the circular patch, the circular patch with four shorting pins, and the annular patch. The positions of the three ports are reasonably arranged based on mode diversity. The measured bandwidth of the port for conical radiation is 35 MHz (2.43–2.465 GHz), while the measured bandwidths of the two ports for broadside radiation are basically the same which is 50 MHz (2.417–2.467 GHz). The measured overall isolation exceeds 50 dB. © 2014 IEEE.