摘要: |
瞬时大宽带信号用移相法进行波束形成时可能会引起波束指偏和孔径渡越导致的脉压畸形,一般需用时间延迟线来解决这个问题,但高精度的射频延迟线工程实现代价很大。本文根据数字阵列雷达和宽带线性调频信号特点,提出了一种基于数字延迟的发射波束形成方法。首先分析了宽带线性调频信号稳定波束指向的约束条件,在此基础上提出了一种DDS采样时钟延迟+同调频斜率扩展波形的延迟的方法。仿真结果表明,该方法对宽带数字阵列雷达的线性调频信号发射波束指偏能够有效纠正和大大减小孔径渡越,不增加系统设备量和运算量,易于工程实现。 |
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DOI:DOI:10.3969/j.issn.1672-2337.2019.06.018 |
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Study on Digital Delay Method for Transmitting Waveform of Wideband Signal |
MING Wenhua,WANG Yue,ZHANG Yonghang
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The 38th Research Institute of China Electronics Technology Group Corporation,Hefei 230088,China
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Abstract: |
Instant wideband signal may result in beamforming misdirection and pulse compression deformity. This problem often needs time delay line,but high precision time delay line needs high price. A digital delay method for wideband transmitting waveform is presented in this paper based on the characteristics of digital array radar (DAR) and wideband linear frequency modulated (LFM) signal. Firstly the constraints of stable beam directivity of wideband LFM signal are analyzed,then a method of extending waveform based on DDS time delay and extended waveform based on the same modulation frequency ratio is presented. The simulation results show that the method can correct the beam directivity offset of DAR effectively and decrease the aperture fill time greatly. The method is easy for realization and doesnt increase hardware and complexity. |
Key words: beamforming wideband signal transmitting waveform digital delay |