부산대학교 도서관

This paper presents the design and development of a compact 3D-printed dielectric meta-lens (DML) antenna intended for ultra-wideband operation in the millimeter-wave frequency range. Initially, cylindrical shaped dielectric unit cells having periodicity of $0.28 \lambda_{0}$ (where, $\lambda_{0}$ is the free-space wavelength at the design frequency i.e. 28 GHz) is designed. Next, the DML structure is crafted by arranging the unit cells in an array of $20 \times 20$ according to the phase distribution required on the lens aperture resulting in an aperture size of $5.6 \lambda_{0} \times 5.6 \lambda_{0}$. The complete DML antenna setup includes a dielectric horn antenna (DHA) positioned at a separation distance of 52 mm from the proposed DML, oriented along the -z-direction held in place with the help of a 3D-printed support structure. Once the DML antenna is fabricated it is assessed for its performance in an anechoic chamber. The experimental results indicate that the antenna attains a maximum measured gain of 23.9 dBi at 28 GHz, signifying a substantial gain enhancement of 9 dB. The measured 3-dB gain bandwidth of 34.4 % is achieved for the proposed DML antenna. Furthermore, the antenna demonstrates an impressive maximum aperture efficiency of 92 %.