%L elediasc12443 %D 2011 %A Giacomo Oliveri %A Leonardo Lizzi %A Andrea Massa %X Polarization-reconfigurable arrays play a fundamental role in radar systems in order to enhance their detection probability and cancel clutters, chaffs, and jammers [1]. In order to reach polarization flexibility, the integration of actively controlled elements in standard array configurations is often employed [2], but the overall system complexity and costs significantly increase [3]. To overcome such limitations, the use of two shared aperture arrays with independent polarizations was proposed in [3] by exploiting an interleaving scheme based on Difference-Sets (DSs). By combining the field generated by each sub-array, arbitrary polarizations, low sidelobes, large steering angles, and narrow beamwidths can be reached with a limited complexity of the underlying feeding network. Despite its theoretical and practical advantages, only few planar array geometries can be synthesized because of the limited number of available DS sequences [4]. A different set of binary sequences [called Almost Difference Sets (ADSs)] [5][6] with properties very similar to those of DSs has been recently investigated. Besides their application in code theory [5], ADSs have already shown their effectiveness in synthesizing thinned arrays with low and predictable sidelobes [7][8]. This paper analyzes the properties of polarization-flexible planar arrays based on ADSs. Numerical simulations are presented and discussed by focusing on the sidelobe level control and the polarization selectivity of the synthesized ADS arrays. %T ADS Interleaved Arrays with Reconfigurable Polarization %I University of Trento %O This version is a pre-print of the final version available at IEEE.