Advanced Electromagnetic Vortex Wave SAR Sidelobe Quality Improvement Imaging Method

It is important to explore the application of electromagnetic vortex (EMV) wave radar carrying orbital angular momentum in the field of SAR imaging as a new type of radar. Due to the unique Bessel antenna pattern modulation and the vortex azimuth angle phase influence in EMV wave radar, the traditional SAR imaging methods result in a decrease in sidelobe quality, which affects the image quality. To address the aforementioned issues, this paper propose an EMV SAR sidelobe quality improvement imaging method. Accurate geometric and signal model for EMV SAR are established. The Bessel antenna pattern and vortex azimuth angle phase compensation functions are designed. And range block division and pattern modification methods are proposed to address the spatial variation and near zero value issues of Bessel antenna pattern issues respectively. Simulation and image evaluation results verified the effectiveness of the proposed method.