Polarization Sensitivity of Antenna Arrays
B. Friedlander · IEEE Transactions on Signal Processing · 2018
The manifold of an array with identical antennas is generally assumed to be insensitive to the polarization of the impinging signal except for a complex scale factor which only affects the signal amplitude. Signal polarization is therefore considered in the literature in the context of diversely polarized arrays, which are specifically designed to be sensitive to polarization. In this paper, we show that the manifold of antenna arrays is generally sensitive to signal polarization even when the antennas have the same polarizations (e.g., identical antennas). We develop two measures which indicate the degree to which an array is sensitive to polarization. We show that direction-of-arrival estimation using an array manifold model which is independent of polarization may be biased due to model mismatch and suffer loss of resolution as the signal polarization varies. Numerical examples are presented to verify the analysis.