Design of Switchable Circularly-Polarized Phased Array Based on Sequential Rotation and 45-degree Rotated Linearly Polarized Elements

In this paper, a novel method is presented to improve the performance of switchable circularly polarized phased array antenna (CPPAA). The CPPAA is designed with 45-degree linearly polarized element (45LPE) rather than conventional pure linearly polarized element (PLPE). Sequential rotation technique (SRT) is applied to achieve circular polarization (CP). Compared with CPPAA using PLPE, the proposed CPPAA not only exhibits high gain but also shows low axial ratio (AR) with wide-angle scanning.