A High-Efficiency Single-Layer Broadband Reflectarray Antenna for 60 GHz Applications

A high-efficiency single-layer broadband reflectarray antenna (RA) for 60 GHz and above wireless communications is proposed in this letter. The design employs a round-corner square ring with an internal cross element, enabling two modes of phase modulation to enhance the bandwidth performance while using only a single PCB layer (0.171λ<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub>) A 20×20-elements RA is designed, fabricated, and tested. Measurement results demonstrate good agreement with simulations, with a measured realized gain of 26.62 dBi at the center frequency of 67.5 GHz, a 3-dB gain bandwidth exceeding 22% (from 60 to 75 GHz), and a maximum aperture efficiency of 40.94%. The proposed reflectarray antenna shows significant potential in high-throughput wireless communications in the 60 GHz license-exempt bands.