Analysis of mutual coupling effect in adaptive array antennas

The performance of an adaptive antenna array is strongly affected by the electromagnetic characteristics of the array. The mutual coupling effect degrades the performance significantly, especially when the inter element spacing is decreased. A method to eliminate the effect of mutual coupling was proposed by R.S. Adve and T.K. Sarkar (see AP-S Int. Symp. Digest, p.1164-67, 1996). The method of moments (MOM) is used to model the mutual coupling effect on the weights and on the final directivity pattern of the adaptive array. Using an example of a two-element half wavelength adaptive dipole array, it is shown that the mutual coupling between the elements of an adaptive array causes significant degradation in the performance of the array and thus should not be neglected. It is demonstrated that, using the algorithm proposed by Adve and Sarkar, the effects of mutual coupling in adaptive arrays can be eliminated successfully.