Circularly Polarized MIMO Antenna Array with Enhanced Characteristics using EBG structure

A broadband circularly polarized MIMO antenna array with a 2×4 feed network was proposed for C-band application. Different unique techniques were utilized in the proposed array to enhance the antenna characteristics, such as gain, 3dB Axial Ratio Bandwidth (ARBW), impedance tuning, and ruinous mutual coupling effects. For a better improvement of circular polarization features, a 2*4 MIMO Sequentially Rotated (MIMO-SR) feed network was used to achieve broader 3dB ARBW. Besides, the MIMO feature of the feed network could control the left- and right-handed CP, respectively. Moreover, electromagnetic band-gap structure was applied to enhance the overall performance of antenna array. Ultimately, specific forms of slot and slit structures were applied onto the top layer of MIMO feed network that provided a high isolation between the radiating elements and array network. The extracted measured results illustrated an impedance bandwidth of 4.6-7.3 GHz at port 1 and 4.25-7.2 GHz at port 2 for VWSR