1-Bit Metasurface-Based Beam-Scanning Circularly Polarized Folded Reflector Antenna
Xi Gao, Jia Qi, Feng Lan, Guofu Wang, Xian Xie, Hao Yi Li
Abstract
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 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> -polarized incident waves and transmits the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</i> -polarized waves into CP waves, and the ERMS is formed by integrating two PIN diodes in each meta-atom. By controlling the <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> – <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> 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 × 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°, and the peak gain and aperture efficiency are 18.8 dBic and about 16.5%, respectively.