Dual-Circularly Polarized Spin-Decoupled Reflectarray With FSS-Back for Independent Operating at <i>Ku</i>-/<i>Ka</i>-Bands
Peng Xu, Long Li, Ruijie Li, Haixia Liu
Abstract
In this work, we propose a new dual-band and dual-circularly polarized spin-decoupled reflectarray (RA) combined with frequency selective surface (FSS)-back that ensure the RA independently operating at <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ku</i> / <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ka</i> dual-band. First, a double-layer FSS with four concentric square loops is designed to inhibit the mutual coupling between the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ku</i> - and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ka</i> -bands. Second, at each <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ku</i> - and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ka</i> -band, the 3 bit coding crossed dipole element is used to realize the spin-decoupling. Moreover, each circularly polarized feed horn generates reflected beam operating with left-hand circular polarization (LHCP)/right-hand circular polarization (RHCP) at <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ku</i> - and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ka</i> -bands, respectively. Finally, the RA with a square size of 340 mm is designed, manufactured, and measured to verify its performance. At 12.45 GHz, the measured cross-polarization levels (XPLs) are better than 16.5 and 18.5 dB for LHCP and RHCP radiations, respectively, which show the great spin-decoupling between the two circular polarizations. The measured XPLs are better than 21 and 22.5 dB for LHCP and RHCP at 30 GHz, respectively. The well-performed RA has the perspective in satellite communication systems at both <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ku</i> - and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ka</i> -bands.