Minimization of mutual coupling effects in eigenstructure algorithms based on modal analysis

The problem of mutual coupling effects between antennas in an adaptive array has not been extensively treated. A general classification of the contributions in this area can be made according to the method of minimizing the effect of mutual coupling. In this way, there are methods that modify eigenstructure (ES) algorithms (both DOA and beamforming) in order to model and eliminate the coupling matrix. These methods are exclusively related to array processing techniques. There are also methods that do not modify the corresponding ES algorithms (for instance MUSIC). These ones seek to correct the actual antenna voltages for the mutual coupling and then process these corrected voltages to determine the angle of arrival. It can be said that these algorithms need two tasks: the first one is related to the electromagnetic problem to find out the coupling matrix while the second one is the application of the non-modified ES algorithm. The method presented in this paper belongs to the second group.