摘要
While many techniques have been developed for the design of different types of antennas,such as wire antenna,patch antenna,lenses,and reflectors,these cannot be said general-purpose strategies for the synthesis and design of antennas to achieve the performance characteristics specified by users.Recently,there has been an increasing need for the development of antenna design techniques because of the advent of 5 G and a variety of space,defense,biological,and similar applications,for which a robust and general-purpose design tool is not to be developed.The main objective of this study is to take a look at antenna design from the field manipulation point of view,which has the potential to partially fulfill this need.We review the existing field manipulation techniques,including field transformation methods based on Maxwell’s and wave equations,point out some limitations of these techniques,and then present ways to improve the performance of these methods.Next,we introduce an alternative approach for field manipulation based on two-dimensional(2 D)metasurfaces,and present laws of the generalized reflection and refraction that are based on 2 D surface electromagnetics.Then,we explore how to overcome the limitations of conventional reflection and refraction processes that are strictly bounded by the critical angle.Finally,we provide some application examples of field manipulation methods in the antenna design,with a view on developing a general-purpose strategy for antenna design for future communication.
尽管人们已经开发了针对不同类型天线的多种设计技术,如线天线、贴片天线、透镜天线以及反射面等,但尚未构建普适的框架技术——普适框架技术应可用于各种天线的综合与设计,使天线具有满足使用者特定需求的电气特性。近年来,5G通信及各种空天技术、国防应用、生物医疗和类似应用的快速发展,迫切需要天线设计技术的大幅提升。本文从场操控角度剖视天线设计技术,为这种框架性构建提供一个可能的思考,以期最终部分满足这种需求。首先,回顾现有操控技术,包括基于麦克斯韦方程和波动方程在内的场变换方法,指出这些技术的局限性,并提出改善性能的方法。其次,介绍一种基于2D超表面的场操控方法及其理论基础——广义反射和折射定律。进一步,探索如何利用2D超表面克服传统的由临界角严格限制的反射和折射局限性。最后,给出场操控方法在天线设计中的应用实例,以期引导人们发展面向未来通信天线设计的通用策略和方法。
基金
Project supported by the National Natural Science Foundation of China(No.61971335).
