采用螺旋线实现高隔离度的车载多频宽带MIMO天线

Implementation of vehicular high isolation multi⁃band wideband MIMO antenna with helical wire

为解决车载天线工作带宽窄和MIMO天线低频段隔离度低等问题,提出一种应用于车载通信系统的多频宽带高隔离度的MIMO天线,其工作频段为824~960 MHz和1710~6000 MHz,可覆盖民用移动通信的2G/3G/4G/5G和无线局域网/车联网等频段。单极子天线单元采用弯曲、开槽等诸多技术实现多频宽带,还通过添加接地枝节来降低天线高度和提高物理稳定性;在MIMO天线设计上采用螺旋线来提高天线单元之间的隔离度。实测结果表明,天线在工作频段内的反射系数小于-10 dB,隔离度小于-20 dB,低频段增益和辐射效率略低,中高频段的增益均大于4 dBi,最高达到7 dBi,效率均高于70%,最高可以达到96%。实测数据与仿真数据具有良好的一致性,所研制的天线可满足车载天线对多频段通信和高隔离度MIMO天线的技术要求,其结构和尺寸专为安装于汽车内部中控台背面而设计。

In view of the narrow operating bandwidth of vehicular antenna and low isolation of multiple⁃input multiple⁃output(MIMO)antenna in low frequency band,a multi⁃band wideband high isolation MIMO antenna applied to vehicle communication systems is proposed.It works in the frequency bands of 824~960 MHz and 1710~6000 MHz,and can cover the frequency bands of civil mobile communication such as 2G/3G/4G/5G and wireless local area network(WLAN)/Vehicle to Everything(V2X).The monopole antenna unit is designed with techniques such as bending and slotting,so as to achieve multi⁃wideband.In addition,the grounded branch is added to reduce the antenna's height and improve its physical stability.MIMO antenna is designed by adopting helical wire to improve the isolation of the antenna unit.The measured results show that the reflection coefficient of the antenna is less than-10 dB and its isolation is less than-20 dB in the operating band,its gain and radiation efficiency is slightly lower in the low⁃frequency band,and in the middle and high⁃frequency bands,its gain is greater than 4 dBi and its maximum is 7 dBi,and its efficiency is higher than 70%and its maximum is 96%.The measured and simulated results have high consistency.The developed antenna can meet the technical requirements of vehicle antenna for multi⁃band communication and high isolation MIMO antenna,and its structure and size are specially designed for mounting on the back of the center console inside the vehicle.