Linear multibeam transmitarray based on the sliding aperture technique

In the massive multiple-input multiple-output systems, the antennas should have the ability of beamforming. Under this requirement, the sliding aperture technique is adopted. In this paper, the principle of the sliding aperture technique is first demonstrated. This technique refers to the customization of each beam by part of the aperture, resulting in low scan loss over a wide angular range. Then, with the help of II-shaped transmit element, a linear multibeam transmitarray antenna based on the sliding aperture technique is designed. To the best of the authors' knowledge, the linear transmitarray is reported for the first time. The fabricated prototype shows that the proposed antenna can generate eight beams simultaneously covering the ±42° azimuth area with low scan loss and the beam intersection level better than -4 dB. The proposed antenna has been simulated, fabricated, and measured, and the experimental results are in good agreement with the simulation results.