On the Polarization Sensitivity of Antenna Arrays

The manifold of an array with identical antennas is generally assumed to be insensitive to the polarization of the impinging signal. We show that the manifold of such arrays is generally sensitive to signal polarization and that ignoring this may degrade the performance of direction-of-arrival estimation algorithms, especially for closely spaced sources. We develop two measures which indicate the degree to which an array is sensitive to polarization.