摘要
作为信息载体的电磁波除了传统的携带信息方式外,近年来其波前以电磁涡旋形式展现的信息调制能力也越来越受到关注。本文综述了电磁涡旋在信息调制等方面的研究进展,阐述了其在雷达信息获取方面的潜在应用价值。针对圆形相控阵列,建立了电磁涡旋波照射下理想点散射目标的回波模型。将各阵元的接收信号按照与发射时相同的模式移相后,沿圆周积分即可获得雷达阵列的输出回波。该回波可表示为经平方Bessel函数调幅后的傅里叶基函数的线性组合。结合Bessel函数的频谱特性,分析了轨道角动量拓扑荷与方位角变量之间的近似对偶关系,利用逆投影和滤波-傅里叶变换方法进行了成像处理。仿真实验表明,电磁涡旋对雷达目标具有方位向成像的潜力。研究可为新体制的雷达设计、目标识别技术的发展提供参考和借鉴。
Amplitude/frequency/phase modulation of electromagnetic（EM） wave, as the common way of carrying information, has received intensive attention recently when the wave front acts as EM vortex for information modulation. The progress on the information modulation capability of EM vortex was systematically summarized and its potential on radar information acquisition was also introduced. Aiming at the circular phased array, the echo signal model of ideal point target was established under the illumination of EM vortex wave. Once the echo signal phase of each antenna element was shifted with the same mode as being applied for submission and integrated along the circular path, the output signal of the radar array can be obtained. The output signal can be modeled as the linear superimposition of Fourier basis with the amplitude modulated by squared Bessel function. According to the spectrum characteristic of Bessel function, the approximate dual relationship between the mode number of orbital angular momentum（OAM） and the variable of azimuthal angle was analyzed. Finally, the back projection（BP） algorithm and filtered FF1r based algorithm were applied to image the target. Simulations show that electromagnetic vortex wave has the potential to acquire the cross-range profile of the radar target. The research may act as a reference for the design of new mechanism radar and the development of target recognition technology.
出处
《国防科技大学学报》
EI
CAS
CSCD
北大核心
2013年第6期71-76,共6页
Journal of National University of Defense Technology
基金
国家自然科学基金资助项目(61002021)
关键词
电磁涡旋
轨道角动量
雷达目标成像
electromagnetic vortex
orbital angular momentum（OAM）
radar target imaging
作者简介
郭桂蓉（1937-），男，四川成都人，教授，博士生导师，中国工程院院士；
胡卫东（通信作者），男，教授，博士，博士生导师，E-mail：wdhu@nudt．edu．cn
