摘要
为了抑制极近距离多输入多输出(MIMO)天线单元间的强耦合,提出了一种将MIMO天线单元的馈电位置邻近排布在激励天线单元电磁场弱场区的解耦方法。其中电磁场弱场区域主要通过改变微带天线的馈电结构产生。为了满足项目特殊需求,首先,设计了一款边到边距离为1 mm(0.011λ_(0),λ_(0)为中心频率3.5 GHz时的自由空间波长)的二单元MIMO天线,仿真和实测结果表明,相比参考天线,利用该解耦方法使MIMO天线在工作频段内的隔离度最大改善了42 dB。进一步地,将改进天线单元沿120°分布构成一款三单元MIMO天线,该天线边到边最小距离仍然为1 mm。实验结果显示在工作频段3.45~3.55 GHz范围内,单元间的耦合抑制大于30 dB;在中心频率3.5 GHz处,测试的最大隔离度为52 dB,且各天线单元的反射系数不受影响。值得一提的是,所提出的解耦方法与传统方法相比,在减少互耦时不需要额外的解耦电路和结构,具有良好的应用前景。
In order to suppress the strong coupling between extremely close-range multiple-input multiple-output(MIMO)antenna elements,a decoupling method is proposed to arrange MIMO antenna elements feeding position in an extreme adjacent distance where belongs to their weak electromagnetic field region.The weak electromagnetic field region is mainly generated by changing the feeding structure of the microstrip antenna.Firstly,a two-element MIMO antenna with an edge-to-edge distance of 1 mm(0.011λ_(0),λ_(0)is the free-space wavelength at the center frequency of 3.5 GHz)is proposed.The simulation and measurement results show that the proposed decoupling method can improve the isolation of the MIMO antenna by 42 dB in the operating frequency band.The isolation performance of the proposed antenna is much more obvious than that of the reference antenna.Furthermore,a three-element MIMO antenna is constructed by arranging the improved antenna elements along 120°.The experimental results show that the coupling suppression is greater than 30 dB in the working frequency band of 3.45~3.55 GHz;the maximum isolation is 52 dB at the center frequency of 3.5 GHz.Moreover,the reflection coefficient of each antenna is not affected by the proposed decoupling structure.It is worth noting that the proposed decoupling method has a good application prospect as it does not need additional decoupling circuit and components compared to the traditional approach with respect to mutual coupling reduction.
作者
杜忠红
张晓晖
秦沛瑜
蒲玉蓉
席晓莉
Du Zhonghong;Zhang Xiaohui;Qin Peiyu;Pu Yurong;Xi Xiaoli(School of Automation and Information Engineering,Xi′an University of Technology,Xi′an 710048,China)
出处
《电子测量与仪器学报》
CSCD
北大核心
2022年第12期161-167,共7页
Journal of Electronic Measurement and Instrumentation
基金
国家自然科学基金(61701398)
国家自然科学基金青年科学基金(62101440)项目资助
关键词
MIMO天线
高隔离度
零场区
弱场耦合抑制
自解耦
MIMO antenna
high isolation
null-field region
weak field coupling suppression
self-decoupling
