In this paper, a novel ultrawideband (UWB) four ports multiple-input multiple-output (MIMO) antenna was developed. The MIMO antenna is based on four wideband circular monopoles with inscribed Fibonacci circles in order to reduce the size and stabilize the impedance over a wider bandwidth. The array shows a frequency bandwidth from 3.6 GHz to 13.8 GHz, obtaining inter-port coupling below −15 dB over the entire bandwidth. Convergent TARC curves over the entire bandwidth exhibit values less than −25 dB and high stability against phase changes in the incoming signals to the different radiators. Finally, the UWB MIMO antenna proposed generates a quasi-omnidirectional radiation pattern with orthogonal properties among radiators, demonstrated by a very small Envelope Correlation Coefficient (ECC) value, averaging 0.005.

本文开发了一种新颖的超宽带（UWB）四端口多输入多输出（MIMO）天线。MIMO天线基于四个内接斐波那契圆的宽带圆形单极子，以减小尺寸并在更宽的带宽上稳定阻抗。该阵列显示3.6 GHz至13.8 GHz的频率带宽，从而在整个带宽上获得低于-15 dB的端口间耦合。在整个带宽上，收敛的TARC曲线显示的值小于-25 dB，并且对不同辐射器的输入信号的相位变化具有很高的稳定性。最后，提出的UWB MIMO天线在辐射器之间生成具有正交特性的准全向辐射方向图，这通过非常小的包络相关系数（ECC）值（平均为0.005）来证明。