Analysis of mutual coupling in adaptive antennas and techniques used for compensation

A single element far field pattern and radiation impedance are different when the same is embedded in an array. This is due to scattering of radiation from nearby elements. When vectors of such scattered radiations are added it changes far field pattern too. Array factor when calculated in isolation with selected amplitudes and phases (weights) for isotropic elements is different. It is due to mutual coupling the end elements and the center elements will have different patterns. It is always desired to place antenna elements closer in order to reduce grating lobes when the main lobe is electrically tilted. In adaptive antenna arrays, mutual coupling can deteriorate the algorithms which try to deal with the direction of arrival (DOA) and beam forming. There is also a need to reduce the size of the antenna aperture and element itself, without degrading the performance and bandwidth of the element. I have attempted to investigate the mechanism for mutual coupling between antenna elements and handled the planar adaptive array algorithm which attempts to mitigate errors and reduces effects of mutual coupling in Matlab.