ABSTRACT

A small size broadband circularly polarized (CP) two-element multiple-input-multiple-output (MIMO) slot antenna with a very low envelope correlation coefficient (ECC) is proposed for ultra-wideband (UWB) applications. Broadband circular polarization is attained by embedding the identical pair of spiral slots, rectangular slot and grounded-L stub on the I-shaped slot antenna. Isolation is achieved through embedding two different slots between mirrored CP square slot antenna elements. The proposed MIMO antenna provides 58.82% (4.8–8.8 GHz) 3-dB axial ratio bandwidth (ARBW), 138.32% (3.17–17.39 GHz) impedance bandwidth (IBW), and more than 16 dB port isolation over the operating band. The MIMO slot antenna size is 40 × 20 mm² with a measured peak gain of about 4.41 dBi and efficiency more than 70%. The diversity performance is computed and presented in detail.

摘要

针对超宽带（UWB）应用，提出了一种具有非常低的包络相关系数（ECC）的小型宽带圆极化（CP）两元素多输入多输出（MIMO）缝隙天线。宽带圆极化是通过将相同的一对螺旋槽，矩形槽和接地的L短截线嵌入I形槽形天线中来实现的。通过在镜像的CP方形缝隙天线元件之间嵌入两个不同的缝隙来实现隔离。拟议中的MIMO天线可提供58.82％（4.8–8.8 GHz）的3-dB轴向比率带宽（ARBW），138.32％（3.17–17.39 GHz）的阻抗带宽（IBW），并在工作频带上提供超过16 dB的端口隔离。MIMO缝隙天线尺寸为40×20 mm ²测得的峰值增益约为4.41 dBi，效率超过70％。计算分集性能并详细介绍。