中文摘要：

文中设计了一款工作在LTE1900（1 880～1 920 MHz）、LTE2300（2 300～2 400 MHz）、LTE2600（2 540～2 650 MHz）频段的移动终端MIMO天线。该MIMO天线采用倒F天线和单极子天线作为天线单元,单元天线折叠成立体结构蚀刻于体积为10 mm×10 mm×5 mm的FR4小方块之上,排布于尺寸为135.0 mm×68.8 mm×1.0 mm FR4介质基板最大表面的短边。利用倒F天线和单极子天线组合,同时辅以地板缝隙的方式来降低近距离天线之间的互耦,地板缝隙不仅可以削弱地板耦合电流以降低天线单元互耦,同时还能改善天线单元的阻抗匹配、拓展天线的带宽。仿真和实测结果表明,天线工作频带内的隔离度大于10 d B,增益大于0.5 d Bi,包络相关系数均小于0.1。

英文摘要：

A new compact three-dimensional triple-band multiple-input multiple-output（ MIMO） antenna system for addressing LTE1900（ 1 880-1 920 MHz）,LTE2300（ 2 300-2 400 MHz） and LTE2600（ 2 540-2 650 MHz） frequency band protocols is designed. The MIMO system is composed of symmetric monopole antenna elements and inverted-F antenna elements. These antenna units are integrated on the FR4 cube with the dimension of 10 mm × 10 mm × 5 mm,which are closely placed along the short edges of an FR4 substrate with the largest surface dimension of 135. 0 mm × 68. 8 mm × 1. 0 mm. By etching the rectangular slits on the ground plane,mutual coupling between the adjacent antenna units is weakened.Moreover,the slits benefit impedance matching and bandwidth enlargement. The simulated and measured results reveal that the mutual couplings between the antenna elements are all less than-10 d B and the envelope correlation coefficients,the gains are greater than 0. 5 d Bi,and the envelope correlation coefficients（ ECCs） are all below 0. 1 in the whole operating frequency bandwidth.