Design of photonic radar transceiver for low-RCS target detection and high-resolution image acquisition

Abstract

however, detection is challenging in modern radar systems due to the low radar cross-section (RCS) of drones and UAVs. A photonic radar has recently attracted attention as a promising solution for identifying a low-RCS target because it has the advantage of being able to generate wideband signals that are beyond the technical limitations of the traditional radar. In this dissertation, an X-band photonic radar transceiver is designed and implemented to detect low-RCS targets and acquire high-resolution images in real-time. Based on theoretical analysis, the photonic radar is designed with a balanced photo-detector to increase signal intensity. Furthermore, an optimal bias voltage search algorithm of an electro-optic modulator is designed for a quadrupling of the center frequency and bandwidth of the intermediate frequency signal, and the designed algorithm is verified through a temperature test. The performance of the implemented photonic radar prototype is verified using a drone as a low-RCS target through the field experiments. In the target detection mode, our field experiment results show that the photonic radar can detect a flying drone 2.7 km away from the radar site. When the drone hovers at 1.1 km from the radar site, the image acquisition mode captures a clear image of the low-RCS target in real-time. Thus, the photonic radar shows the feasibility of developing a next-generation radar capable of detecting and identifying low-RCS targets.

As drone and unmanned aerial vehicle (UAV) technology advances, asymmetric threats such as bombing using UAVs have increased significantly. To prevent the threat of drones and UAVs, it is critical to identify them in advance