A MIMO antenna: Study on reducing mutual coupling and improving isolation

MIMO antenna has gained lot of attention for research today due to various advantages such as increase in capacity, low signal loss and less multipath fading. Although it has many benefits, the main challenge lies in the design of MIMO Antenna i.e to reduce the mutual coupling between the antenna element and to provide high isolation. To reduce the mutual coupling and for improving the isolation, various techniques are employed such as Defected Ground Structure such as slits, slot, spiral square structure, EBG structure, U shaped parasitic element, stubs, neutralization line, parasitic elements, etc. The mutual coupling of more than 20 dB is obtained by employing all these technique. The main focus of this paper is to present and compare the different technique to reduce the mutual coupling and increase the isolation for various frequency bands.