Mutual coupling in six element microstrip antenna array with different element spacings was examined. Linear antenna array pattern correction using pseudoinvariance was tested. Also reflected power statistics was evaluated in simple cases of antenna array input coefficient statistics [1,2]. The pattern correction gives new input coefficients, so that the corrected pattern is closer to desired. In the case of adaptive array with different inputs we can store the correction matrix and use it for any feeding vector to correct the array pattern. For adaptive antennas the reflected power due to mutual coupling is a problem causing system performance decrease and even damages. The total reflected power is feeding vector dependent. The extreme levels of reflected power are the extreme eigenvalues of the scattering matrix.