Wideband and low-profile transmitarray antenna using transmissive metasurface

Based on the Pancharatnam-Berry phase principle, a wideband low-profile transmissive metasurface was designed and applied to a transmitarray antenna (TA). While a full transmission phase range of 360° was achieved by rotating the proposed unit cell, the transmission coefficient was always close to 1 in the frequency range of 10.4-11.6 GHz. Hence, a TA comprised of 20 × 20 unit cells of size 180 mm × 180 mm was designed and fabricated. The simulated results agreed well with the experimental data, validating the excellent performance of the proposed metasurface structure. The measured peak gain of the TA was 21.64 dB at 11 GHz, resulting in an aperture efficiency of 34%. In addition, we attained a 12% 1-dB gain bandwidth (10.2-11.5 GHz) and an 18% 3-dB axial ratio bandwidth (10-12 GHz) for the TA. The proposed metasurface exhibits distinct performance benefits in terms of having wide bandwidth, low-profile, and high-efficiency, as well as represents a promising design option for a high-performance TA.