Intrinsic Polarization in Polarimetrically Beamformed Arrays with Differentially Rotated Elements

Paper in proceeding, 2023

Prior characterization of the sub-systems of a radio telescope which also works as a radio polarimeter is essential in view of the polarimetric performance understanding and the implementation of the most appropriate calibration procedure. In this paper the polarimetric characterization of two phased antenna arrays having identical antennas and array factors but different antenna alignment will be discussed. These arrays have been proposed as possible layouts in the SKA-Low framework. The polarimetric beamforming, i.e. the beamforming for dual-polarized antennas, has been applied to calculate the polarization purity of the two arrays across the sky. In particular we investigated the variation of instrumental polarization along azimuthal cuts and found that the variation was less in the array in which elements had different alignments compared to the one where all elements had the same alignment.