Reading chipless RFID located on metallic platforms by using cross-polar scattering

Aim of this paper is to design a fundamental building block of a spectral domain chipless RFID system based on cross-polar scattering. A novel chipless tag able to provide multi-frequency polarization conversion is proposed. The tag is able to convert the polarization of impinging electromagnetic fields at multiple frequencies guaranteeing good polarization conversion both for vertical, horizontal and oblique azimuthal incidence without introducing additional unwanted high-order resonances. The use of such tags allows a very low-cost tagging of very large metallic platforms regardless of their dimensions and their huge echo.