A Circularly Polarized Folded Reflectarray Antenna with ME Dipole Feed at K-Band

In this work, a circularly polarized folded reflectarray antenna (CPFRA) with a linearly polarized feed was proposed for K-band satellite communication uplinks. The main reflector consists of double quasi-I-beam elements achieving 360<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∘</sup> phase shifts and linear polarization rotation. A polarization-selective surface is used as the sub-reflector, and its linear polarization reflection efficiency and circular polarization conversion are analyzed. Moreover, a magneto-electric (ME) dipole antenna is designed as the feed, offering wide bandwidth, low cross-polarization, and ease of integration with the main reflector. The proposed CPFRA features a low profile, compact structure, and a low axial ratio. Simulation results demonstrate that the antenna achieves a 1-dB gain bandwidth of 19.16% (17.7-21.45 GHz), a 3-dB axial ratio (AR) bandwidth of 8.46% (19.24-20.94 GHz), and a maximum gain of 22.5 dBi at 20 GHz.