A wideband MIMO antenna using leaf-shaped monopole and notch antennas

This paper presents a design of a wideband 4-port antenna array being useful for MIMO applications. In the designed antenna array that operates over the frequency band of 7.25-10.25 GHz, a leaf-shaped monopole and notch antennas are employed as the array elements. By using these orthogonal polarization elements, both low coupling level between adjacent array elements and miniaturization of the antenna structure are realized. In order to demonstrate the effective performance of the presented configuration, characteristics of the designed MIMO antenna are evaluated by the finite-difference time domain (FDTD) analysis. Over the above-mentioned frequency band, the designed antenna has the reflection coefficient of less than -10 dB and the mutual coupling between ports below -12 dB. In addition, the antenna port envelope correlation coefficient is observed to be less than 0.22.