Polarimetry With Phased Array Antennas: Sensitivity and Polarimetric Performance Using Unpolarized Sources for Calibration

Polarimetric phased arrays require a calibration method that allows the system to measure the polarization state of the received signals. In this paper, we assess the polarimetric performance of two commonly used calibration methods that exploit unpolarized calibration sources. The first method obtains a polarimetrically calibrated beamforming solution from the two dominant eigenvectors of the measured signal covariance matrix. We demonstrate that this method is sensitivity equivalent to the theoretical optimal method, but suffers from an ambiguity that has to be resolved by additional measurements on (partially) polarized sources or by exploiting the intrinsic polarimetric quality of the antenna system. The easy-to-implement bi-scalar approach assumes that the feed system consists of two sets of orthogonally oriented antenna elements, each associated with one polarization. We assess its sensitivity and polarimetric performance over a wide field-of-view (FoV) using simulations of a phased array feed system for the Westerbork Synthesis Radio Telescope. Our results indicate that the sensitivity loss can be limited to 4.5% and that the polarimetric performance over the FoV is close to the best achievable performance. The latter implies that the intrinsic polarimetric quality of the antennas remains a crucial factor despite the development of novel polarimetric calibration methods.

TEKNIK OCH TEKNOLOGIER Elektroteknik och elektronik hsv//swe
ENGINEERING AND TECHNOLOGY Electrical Engineering, Electronic Engineering, Information Engineering hsv//eng
self-calibration
calibration
far-field radiation pattern
polarimetry
dynamic-range
wide-field
understanding radio polarimetry
Beamforming
phased array antennas

Ivashina, Marianna,1975Chalmers tekniska högskola,Chalmers University of Technology(Swepub:cth)ivashina (author)
Maaskant, Rob,1978Chalmers tekniska högskola,Chalmers University of Technology(Swepub:cth)maaskant (author)
Warnick, K. F.Brigham Young University (author)
Netherlands Institute for Radio Astronomy (ASTRON)Chalmers tekniska högskola (creator_code:org_t)

In:IEEE Transactions on Antennas and Propagation60:10, s. 4688-46980018-926X1558-2221

By the author/editor: Wijnholds, S. J.; Ivashina, Marian ...; Maaskant, Rob, 1 ...; Warnick, K. F.

About the subject

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.