基于角度分集的机载超宽带MIMO天线设计

为了提高机载通信设备信道容量和进一步减小天线安装空间，提出一种采用角度分集技术的超宽带（UWB）多输入多输出（MIMO）天线。该天线将Vivaldi天线和超宽带槽天线进行了集成设计，无需采用解耦结构便可获得较高的端口隔离度，大大提高了数据传输率。通过在Vivaldi天线辐射臂上开一对方形缝隙和在介质板背面增加长方形辐射贴片，可以有效减小天线的尺寸，设计的UWB-MIMO天线尺寸为36 mm×36 mm×0.8 mm。给出了天线的设计流程，加工了天线实物，并对其进行了测量。仿真和实测结果表明MIMO天线具有超宽的阻抗带宽，可以覆盖整个3.1~10.6 GHz超宽带频段。Vivaldi天线阻抗带宽为2.8~15.9 GHz，UWB槽天线阻抗带宽为1.8~12.7 GHz，天线端口隔离度均在-10 dB以下。测量了天线的辐射性能和增益特性，实测结果与仿真结果吻合较好，证明了该天线的有效性。该天线可以应用于超宽带无线通信系统和机载阵列天线系统中。

Design of airborne ultra wideband MIMO antenna based on angle diversity

In order to increase the channel capacity of airborne communication equipment and further reduce the installation space of the antenna, an Ultra WideBand (UWB) Multiple Input Multiple Output (MIMO) antenna with angle diversity is proposed. This antenna integrates Vivaldi antenna and UWB slot antenna to obtain high port isolation without adopting the decoupling structure, greatly improving the data transmission rate. The size of the antenna can be effectively reduced by opening a pair of square slots on the Vivaldi antenna arm and adding a rectangle radiating patch on the back of the dielectric plate. The size of the designed UWB-MIMO antenna is 36 mm×36 mm×0.8 mm. The design process of the antenna is given, and the antenna is fabricated and measured. The simulated and measured results show that the MIMO antenna has an ultra wide impedance bandwidth and can cover the entire 3.1 to 10.6 GHz UWB. The impedance bandwidth of the Vivaldi antenna is 2.8 to 15.9 GHz and the impedance bandwidth of the UWB slot antenna is 1.8 to 12.7 GHz. The port isolation of the antenna is below -10 dB. The radiation performance and gain characteristics of the antenna are measured. The measured results are in good agreement with the simulated results, which proves the effectiveness of the antenna. The antenna can be applied to UWB wireless communication system and airborne array antenna system.