基于特征模理论的低剖面MIMO立方体天线

Low-profile MIMO cube antenna based on characteristic mode theory

基于特征模理论,给出了一种适用于室内环境的16端口多输入多输出(MIMO)立方体天线设计.首先利用特征模理论在对一个矩形金属片进行模式分析的基础上,同时激励金属片的不同模式,设计了一款工作于5. 150～5. 875GHz的高隔离度的4端口MIMO天线单元,并引入人工磁导体(AMC)表面代替原天线的地板,大大降低了天线的剖面.进一步地,围绕立方体环绕一周组成4×4端口的MIMO立方体天线,在较小的空间内实现了天线的多端口与多极化.仿真和测试结果表明:天线在5. 150～5. 875 GHz频段内端口反射系数S_(ii)<-10 dB,端口间隔离度|S_(ij)|> 20 dB.

Based on the characteristic mode theory,a 16-port multiple-input multiple-output(MIMO)cube antenna design for an indoor environment is presented.First,a high-isolation 4-port MIMO antenna unit operating at 5.150-5.875 GHz is designed by exciting different modes of a rectangular plate simultaneously,based on a modal analysis using the characteristic mode theory.An artificial magnetic conductor(AMC)surface is introduced to replace the reflector of the original antenna,which greatly reduces the profile of the antenna;it is also used to surround the antenna to form a 16-port(4×4)MIMO cube antenna.This antenna fulfils the multi-port and multi-polarization requirement within a small space.The simulation and experimental results show that the antenna operates with a port reflection coefficient Sii<-10 dB and port isolation|Sij|>20 dB in the 5.150-5.875 GHz band.