Calibration of panelized polarimetric phased array radar antennas: A case study

Demand for improvements in the performance and capabilities of new polarimetric radar systems beyond those of their predominantly mechanically-rotated predecessors has led to an effort to realize large, dual-polarized phased array an-tennas. These arrays have changing polarization characteristics with scan angle, requiring calibration and compensation. This paper provides a qualitative discussion of the challenge in meeting polarime-tric weather radar requirements, such as a low bias in differential reflectivity (Z_DR) and integrated cross polarization ratio (ICPR). A case study is presented using low-cost, aperture-coupled, stacked-patch antennas, a representative example of what may be used in large polarimetric phased array applications, to predict quantitatively the performance that can be achieved through suitable calibration and size constraints.