A frequency diverse array (FDA) radar has attracted wide attention, due to its capability to provide a range-angle dependent beampattern and to scan the spatial without phase shifters or rotating arrays. However, FDA systems will suffer from low echo signal energy or high sidelobe peaks when detecting targets by beamforming based on existing receivers. To reduce the sidelobe peak of detection results while increasing the echo signal energy, in this paper, we propose an FDA radar system based on diversity linear frequency modulation waveforms. Correspondingly, we propose a receiver architecture with a time-variant beamforming chain. The proposed system retains the ability of the FDA system to automatically spatial beam scanning, owing to the frequency increment across elements. By increasing the pulse duration of transmitted signals, we enhance the echo signal energy. By applying the artificial bee colony algorithm to design the bandwidth of each chirp signal, the proposed system reduces the sidelobe level of detection results while increasing pulse width. Numerical simulation results are presented to demonstrate the effectiveness of the proposed system.

中文翻译：

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一种基于分集线性啁啾波形的频率分集系统波形设计方法

频分阵列 (FDA) 雷达已引起广泛关注，因为它能够提供与距离角相关的波束图案，并且无需移相器或旋转阵列即可扫描空间。然而，FDA 系统在基于现有接收器通过波束成形检测目标时，会遇到低回波信号能量或高旁瓣峰值的问题。为了在提高回波信号能量的同时降低探测结果的旁瓣峰值​​，本文提出了一种基于分集线性调频波形的FDA雷达系统。相应地，我们提出了一种具有时变波束形成链的接收器架构。由于跨元件的频率增加，所提议的系统保留了 FDA 系统自动进行空间光束扫描的能力。通过增加传输信号的脉冲持续时间，我们增强了回波信号的能量。通过应用人工蜂群算法设计每个啁啾信号的带宽，该系统降低了检测结果的旁瓣电平，同时增加了脉冲宽度。数值模拟结果展示了所提出系统的有效性。