基于多径信道模型研究时间反演腔的反演特性  

Analysis of time reversal cavity characteristics based on multipath channel model

作　　者：陆希成 邱扬[1] 田锦[1] 汪海波 江凌 陈鑫[1,3] Lu Xi-Cheng;Qiu Yang;Tian Jin;Wang Hai-Bo;Jiang Ling;Chen Xin(College of Mechanical and Electrical Engineering,Xidian University,Xi’an 710071,China;Northwest Institute of Nuclear Technology,Xi’an 710024,China;Institute of Electronic Engineering,China Academy of Engineering Physics,Mianyang 621999,China)

机构地区：[1]西安电子科技大学机电工程学院,西安710071 [2]西北核技术研究院,西安710024 [3]中国工程物理研究院电子工程研究所,绵阳621999

出　　处：《物理学报》2022年第2期67-72,共6页Acta Physica Sinica

摘　　要：基于时间反演腔的电磁波时间反演技术在许多方面有着潜在的应用,如脉冲压缩、功率合成、微扰探测、波束成形等.其中,时间反演腔通常采用具有多径传输特征的微波混沌腔.利用衍射理论,虽然可以证明这类腔体在时间反演过程中具有时空聚焦特性并可用于脉冲压缩,但是它不能用于分析腔体的反演性能.为了得到一个合适的分析方法并可用于指导时间反演腔设计,本文基于信道理论,分析电磁波传播的散射、扩散和衰减特性,构建了时间反演腔的多径信道模型,并详细研究了路径之间的串扰特征,给出反演重构信号的时间旁瓣产生机理、时移特征以及对主瓣的干扰情况.另外,根据随机平面波假设,还分析了空间焦斑的分布特征.实际焦斑大小不但受限于衍射极限而且还与初始焦斑大小有关.这些理论分析结果与实验和数值仿真结果基本一致.The electromagnetic wave time reversal technology using time reversal cavity(TRC)has potential applications in many areas,such as pulse compression,power synthesis,perturbation detection,beamforming,etc.Microwave chaotic cavity with multi-path transmission characteristics is usually used in TRC.Based on diffraction theory,it can prove that this kind of cavity has spatiotemporal focusing characteristics and can be used for compressing pulses,but it cannot be used to analyze the reversal performance of the cavity.In order to obtain a suitable analysis method and guide the design of TRC,in this work,the scattering,diffusion and attenuation characteristics of electromagnetic wave propagation are analyzed and a multipath channel model of TRC is built by the channel theory.Moreover,the crosstalk characteristics between paths are studied,and the generation mechanism of time sidelobe,time sidelobe shift and interference are also investigated.In addition,under the assumption of random plane wave,the distribution characteristics of spatial focal spot are analyzed,which is consistent with the diffraction theory.Moreover,the actual focal spot size is not only limited by the diffraction limit,but also related to the initial focal spot size.The theoretical analysis results are basically consistent with the experimental and numerical simulation results.

关 键 词：时间反演腔 多径信道模型 路径串扰 随机平面波 

分 类 号：O441.4[理学—电磁学]