Design, fabrication, and measurement of efficient beam-shaping reflectors for 5G mm-wave applications

Karaova, Gökhan Çağlayan
In this study, an optimization procedure to design corrugated passive metallic reflectors for the fifth-generation millimeter wave (5G mm-wave) applications, as well as the fabrication and measurement of the designed reflectors, are presented. Such reflecting surfaces can be used as passive repeaters in both indoor and outdoor applications to change the field coverage by redirecting incident beams into desired directions with controllable power distributions. The design procedure includes a heuristic optimization method (genetic algorithms (GAs)) and full-wave electromagnetic analyses. For efficient and effective optimization of complex geometries, a multigrid approach is used. In this approach, the number of surface representation points is gradually increased in the course of an optimization to reach the best designs via a dynamic process from coarse shaping to fine tuning. Multilevel fast multipole algorithm (MLFMA) is used for the required full-wave electromagnetic analyses by reducing the computation time substantially without deteriorating the accuracy. The optimized geometries are fabricated using a three-dimensional (3D) printing method that enables low-cost and adaptive fabrication. The fabricated 3D prints are coated with a low-cost conductive paint to obtain the final reflectors. Measurements are performed using a Naval Radio Lab arch (NRL arch) and in a free-space setup. The measured results are in good agreement with the simulations, demonstrating the success of both the design procedure and the designed reflectors as efficient 5G components. The designed reflectors provide solutions to the demand for low-cost and energy-efficient signal repeaters needed in 5G mm-wave mobile communication. Thanks to the adaptive design procedure and the use of 3D printing technology, the proposed types of reflectors can be realized and implemented for diverse configurations and alternative scenarios, where the distribution of the signal needs to be controlled in free space. Finally, the designs presented in this study have large bandwidths, while they are also scalable for alternative frequency ranges.
Citation Formats
G. Ç. Karaova, “Design, fabrication, and measurement of efficient beam-shaping reflectors for 5G mm-wave applications,” M.S. - Master of Science, Middle East Technical University, 2021.