High-Resolution FMCW Radar for Small UAV Detection Using GNU Software-Defined Radio

This article presents a threat detection system for Unmanned Aerial Vehicles (UAVs) designed to enhance operational security in high-risk environments. The system employs Frequency Modulated Continuous Wave (FMCW) radar, optimized to detect UAVs with a radar cross section (RCS) as small as 0.01 m², exemplified by models such as the DJI Phantom 3 and Phantom 4. Operating at 2.45 GHz, the radar achieves a maximum detection range of 300 meters and is implemented on the USRP B210 Software Defined Radio (SDR) platform, with real-time signal processing enabled through GNU Radio and integrated GPU resources. The transmission module includes a 100-watt Power Amplifier (PA) and dual-parabolic unidirectional antennas, while the receiver employs a Band-Pass Filter (BPF) and a Low Noise Amplifier (LNA) with a gain of 20 dB to improve sensitivity to reflected signals. The USRP B210 handles signal acquisition and processing, applying two-dimensional Fast Fourier Transform (FFT) techniques to extract doppler shift information. The processed data is visualized as a range-doppler map, facilitating effective target tracking. The system's modular architecture and parallel processing capability enable precise and efficient detection of low-RCS UAVs, even in cluttered environments. This work demonstrates a practical, cost-effective radar solution for security-sensitive applications, offering advantages in performance, adaptability, and real-time capability over traditional radar systems.