Low Mutual Coupling Four-Port MIMO Antenna Array for 3.5 GHz WiMAX Application

A low mutually coupled four-port MIMO antenna design for 3.5 GHz WiMAX application is presented in this article. This array consists of four monopole antennas interconnected with a neutralization line network. Using the S-parameters and surface current plots, the working mechanism of antenna array is explained. The -10 dB impedance bandwidth ranges from 3.37 GHz to 3.61 GHz. The combination of the neutralization line network and the H-shaped periodic structures along with a grounded rectangular loop reduces the mutual coupling by 7.5 dB within the operating frequency range and is found to be ≤ -17.5 dB. Envelope correlation coefficient is noted to be less than 0.1 and gain is noted to be between 2.71 dBi and 2.83 dBi.