Improving millimeter-wave imaging quality using the vortex phase method  

作　　者：Nairui Hu Feng Qi Yelong Wang Zhaoyang Liu Pengxiang Liu Weifan Li 

机构地区：[1]Key Laboratory of Terahertz Imaging and Sensing,Shenyang 110169,China [2]Shenyang Aerospace University,Shenyang 110136,China [3]Key Laboratory of Opto-Electronic Information Processing,Chinese Academy of Sciences,Shenyang 110169,China [4]Shenyang Institute of Automation,Chinese Academy of Sciences,Shenyang 110169,China [5]Institutes for Robotics and Intelligent Manufacturing,Chinese Academy of Sciences,Shenyang 110169,China [6]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Defence Technology（防务技术）》2024年第9期193-202,共10页Defence Technology

基　　金：Science,Technology and Innovation Project of Xiongan New Area (Grant No.2022XAGG0181);LiaoNing Revitalization Talents Program (Grant No.XLYC2007074);Shenyang Young and Middle-aged Science and Technology Innovation Talent Support Program (Grant No.RC220523);Natural Science Foundation of Liaoning Province of China (Grant Nos.2022-YGJC-03 and 2022-MS-034)to provide fund for conducting experiments。

摘　　要：This paper investigates a new vortex wave imaging approach to improve the imaging quality of small metal targets of size less than 1.5 mm.Antennas with different spiral phase plates are designed to efficiently transmit vortex beams with orbital angular momentums(OAMs).By analyzing the OAM spectrum of the target,it was discovered that the predominant reflection contains a particular OAM mode that carries abundant azimuthal information.This can be explained by the OAM selectivity of the target and the guidance of the vortex transmitting beam.A simple reflection vortex imaging system was designed to capture the phase information.Measurement results show that the high image contrast reaches 14.9%,which is twice as high as that of the imaging without OAM.Both of simulations and experiments demonstrate that the vortex phase imaging approach proposed in this paper can effectively improve the imaging quality at 80 GHz.This approach is suitable for other millimeter wave imaging systems and is helpful to improve the resolution in anti-terrorism security checks.

关 键 词：Orbital angular momentums(OAMs)beams Focal plane imaging Spiral phase plates(SPPs) Vortex spectrum 

分 类 号：O441.4[理学—电磁学] TJ5[理学—物理]