频率扫描阵列的ISAR成像技术

逆合成孔径雷达（ISAR）需要发射宽带信号，在与频率扫描阵列联合应用时，由于频率扫描阵列各阵元间馈线产生的相位差不能匹配发射或者接收信号频率的变化，因此该阵列在进行ISAR成像时对信号瞬时带宽有较大的约束。针对上述问题，论文将频率分集成像技术应用在频率扫描阵列上，通过不同时刻发射不同频率单频信号合成宽带，并且频率变化适用于频率扫描阵列的波束指向调节。该方法既能形成波束指向目标，又可以克服频率扫描阵列发射宽带信号时的限制，完成ISAR二维成像。在建立该方法的基础上，还针对阵列参数与目标航迹参数等对成像的影响进行了分析。结果表明，所提的频率分集ISAR成像技术，可在频率扫描阵列上实现对运动目标的二维成像。

Inverse Synthetic Aperture Radar Imaging Technology Based on Frequency Scanning Array

Inverse synthetic aperture radar (ISAR) needs to transmit broadband signals. When combined with frequency scanning array, because the phase difference generated by the feeders between the elements of the frequency scanning array can not match the change of the transmitted or received signal frequency, the array has great constraints on the instantaneous bandwidth of the signal during ISAR imaging. In order to solve the above problems, frequency diversity imaging technology is applied to frequency scanning array in this paper. By transmitting single frequency signals with different frequencies at different times, broadband is synthesized, and frequency variation is suitable for beam pointing adjustment of frequency scanning array. This method can not only form the beam to point at the target, but also overcome the limitation of the frequency scanning array in transmitting broadband signal, so as to complete the ISAR two-dimensional imaging. On the basis of this method, the influence of array parameters and target track parameters on imaging is analyzed. Finally, the results show that the proposed frequency diversity ISAR imaging technology can achieve two-dimensional imaging of moving targets on the frequency scanning array.