The development of radar technology for the detection of small drones is getting attention of researchers. In this work, the detection of drones using Ku-band radar system has been discussed. We have utilized the advantage of nonlinear frequency modulation (NLFM) waveform for the suppression of range sidelobes. The performance and sensitivity of a radar system can be related with the linearity of system response. Here, we have made an effort to minimize non-linearity in the radar system response by using digital predistortion method. In this method, amplitude weighting coefficients have been calculated based on the received data. We have used FPGA-based transceiver for intermediate frequency (IF) signal generation and data acquisition, along with Ku-band up-down converters. The radar system was first calibrated for desired frequency band using amplitude predistortion method. In this article, experiment results for the detection of single drone and two drones using NLFM pulse signal are presented.

中文翻译：

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使用预失真技术进行无人机探测的 NLFM 脉冲雷达

用于探测小型无人机的雷达技术的发展正受到研究人员的关注。在这项工作中，已经讨论了使用 Ku 波段雷达系统检测无人机。我们利用非线性频率调制 (NLFM) 波形的优势来抑制距离旁瓣。雷达系统的性能和灵敏度与系统响应的线性度有关。在这里，我们努力通过使用数字预失真方法来最小化雷达系统响应中的非线性。在该方法中，已经根据接收到的数据计算了幅度加权系数。我们使用基于 FPGA 的收发器以及 Ku 波段上下转换器来生成中频 (IF) 信号和数据采集。首先使用幅度预失真方法针对所需频段校准雷达系统。在本文中，介绍了使用 NLFM 脉冲信号检测单架无人机和两架无人机的实验结果。