1-Bit Metasurface-Based Beam-Scanning Circularly Polarized Folded Reflector Antenna

A circularly polarized (CP) and electronically reconfigurable folded reflector antenna (ERFRA), which has wide-angle beam scanning performance, is developed and demonstrated. The CP-ERFRA comprises a receiver-transmitter metasurface (RTMS), an electronically reconfigurable metasurface (ERMS), and a metallic patch acting as the feeding source. The RTMS completely reflects the x-polarized incident waves and transmits the y-polarized waves into CP waves, and the ERMS is formed by integrating two PIN diodes in each meta-atom. By controlling the on-off state of PIN diodes, the ERMS can achieve 1-bit phase encoding and linear polarization conversion. Due to these RTMS and ERMS properties, the ERFRA can generate CP radiation with beam-control ability. A 16 x 16 CP-ERFRA is fabricated and tested to verify the feasibility of the proposed design. The experimental results show that the beam scanning angle is up to +/- 50 degrees , and the peak gain and aperture efficiency are 18.8 dBic and about 16.5%, respectively.