Analysis of high-speed target imaging based on vortex electromagnetic wave

Abstract

The wavefront of Vortex electromagnetic wave (VEMW) is helical in the spatial distribution and different orbital angular momentum (OAM) modes l are orthogonal to each other, which effectively improve the imaging and detection capability of radar. The traditional echo signal "stop and go" hypothesis will produce mismatch filtering and Doppler coupling time shift caused by the intrapulse Doppler term for high-speed targets. In addition, the azimuth of the target coupled with the OAM mode will also be blurred, resulting in deterioration of the imaging quality. For this problem, this paper analyzes the high-speed target imaging based on vortex electromagnetic waves to explore the factors that affect the imaging quality. Firstly, the imaging model for high-speed target is deduced and the echo signal expression is analyzed. On this basis, the phase term formed by the high-speed motion in the echo is analyzed. The simulation results show that the imaging quality is effectively improved after the error phase term obtained from the theoretical analysis is compensated. This work can provide suggestions for subsequent work on vortex imaging of high-speed targets.