Mutual coupling effects on adaptive antenna arrays

The authors examine the effects of mutual coupling on an adaptive array system and propose the use of scalar spherical modes (SSMs) to predict and correct the problem. Preliminary results are presented: the receive patterns of an ideal ten-element half-wave dipole array and a ten-element half-wave dipole array with mutual coupling are shown. A desired signal is incident at 20 degrees and an undesired signal at 60 degrees with 400 times the power of the desired signal. The effect of mutual coupling is to raise the null level in the undesired signal direction by approximately 25 dB. The validity and applicability of the SSM approach have been demonstrated.<>