Review and engineering application challenge of multi-beam lens antennas

The advancement of wireless communication technology and the development trend of broadband and high-throughput lead to the emergence of multi-beam antennas with high gain and flexible beam characteristics. Multi-beam lens antennas are passive multi-beam antennas that achieve multiple independent beams using the structure of the lens itself. It has the advantages of low cost, wide band, wide angle scanning, and simple structure. This article aims to summarize various types of lens antennas and offer insights into the future development direction of lens antennas, based on their structure, electromagnetic characteristics, and the requirements of future engineering applications. Firstly, it introduces the basic principles and application directions of Rotman lens, and then focuses on the research progress of Luneburg lens, including working principles, manufacturing processes, and characteristics of two types of Luneburg lenses (dielectric and metal). It also introduces flat lenses including Fresnel zone plate and metasurface lenses. Finally, it points out the challenges faced by lens multi-beam antennas in engineering applications, hoping to provide reference for future in-depth research and engineering applications.