非线性频偏FDA对测向系统的欺骗研究

Research on the Deception of Direction-Finding System Based on FDA with Non-Linear Frequency Offset

与相控阵仅具有角度相关性的波束指向不同,频率分集阵列FDA通过在阵元间引入频偏的方式实现了具有更高自由度的电扫描波束。雷达方向侦查中,基于相位法测向的干涉仪通过比相器可以得出辐射信号到达接收机的相位、确定PA辐射信号到达角,威胁雷达安全。针对这一问题,基于FDA波束的“弯曲”特性研究了对敌方雷达方向侦查过程实现测向欺骗的可能。在通过非线性频控函数设计实现FDA波束图距离-角度解耦的基础上,仿真验证了远场条件下log-FDA、sin-FDA可对干涉仪测向产生欺骗,证明FDA对干涉仪测向的影响随着频偏增量Δf和阵元间距d增大而增强,且log-FDA始终比sin-FDA的性能更好。

Unlike the beam pointing of phased array(PA),which is only angularly related,the beampattern of frequency diversearray(FDA)achieves electrical scanning with higher degree of freedom by introducing a frequency offset between array elements.In view of the problem that in radar direction detection,the interferometer can determine the arrival angle of the radiation signal by obtaining the phase difference of the radiation signal reaching the receiver through the phase comparatorwhich will threaten the safety of radar.Based on the“bending”characteristic of the FDA’s beam pattern,this paper studies the possibility of angle deception in the direction detection of enemy radar.Based on the range-angle decoupling technologyrealized by FDA using nonlinear frequency offset,we can provethat log-FDA and sin-FDA can deceive interferometer direction finding under far-field conditions.And the deceptive effect of log-FDA is better than that of sin-FDA.We can also draw conclusionsthat the deceptive effect will enhance with the increase of frequency offset Δf and the array spacing d.