A hybrid decoupling technique for mutual coupling improvement of polarization diversity MIMO antenna

This paper proposes the improvement analysis of the mutual coupling for a dual-polarized antenna array with the introduction of parasitic elements at low frequency. the 4 × 4 antenna array with 16 dipole antennas have a star configuration with slanted ± 450 dipole antennas and antenna spacing; d = λ/2. the parasitic elements are located in between the antenna array with the spacing of λ/4. in this study,the height of the parasitic element is varied with respect to the height of the dipole antenna. the analysis result shows that the maximum improvement of the mutual coupling can be achieved when the height of the parasitic element is half of the height of the dipole antenna with the existence of dual-polarized radiation pattern. a maximum improvement of 19 db can be achieved to provide an antenna isolation of 37 db with this hybrid decoupling technique.