Reduction of Cross-polarization on a Single Offset Parabolic Reflector using Digital Beam Forming Techniques and Combination of Elements

The antenna configuration studied is part of Tandem-L project, a proposal for interferometric radar mission to monitor the Earth. It consists of a large deployable reflector antenna in offset configuration with a digitized feed. The high crosspolar level due to the reflector geometry must be compensated to fulfil the requirements of fully polarimetric applications. Synthetic Aperture (SAR) calibration methods known until now are not able to reduce the crosspolar component of the radiation pattern of single offset reflector antennas. A reduction of the antenna crosspolar level must be performed in the antenna design stage. This paper shows the characterization and combination of two different techniques to reduce the crosspolar level of a large deployable single offset parabolic reflector.