中文摘要：

在多输入多输出（Multiple-InputMultiple-Output，MIMO）雷达成像系统中，天线阵列配置是系统设计的一个关键问题，影响到成像质量、参数估计和目标检测等。阵列的拓扑结构、阵元数量及发射信号的形式等都会影响阵列设计的结果，合理的阵列设计有利于简化系统结构并降低信号处理的复杂度。与传统窄带分析有所不同，在超宽带条件下天线阵列表现出一些新的性质，可以用于实现阵列的稀疏化。本文推导了超宽带多输入多输出阵列角分辨率和旁瓣、栅瓣水平的计算式，提出了一种针对步进频率信号体制的超宽带多输入多输出阵列优化设计方法，仿真数据处理结果验证了本文方法的有效性。

英文摘要：

In Multiple-Input Multiple-Output （MIMO） imaging applications, the configuration of antenna array is one of the key techniques for system design. It has great effects on imaging quality, parameters estimation and targets detection. The performance of the array is related not only to the topology of the array and the number of array elements, but also the spectrum of the radiated signal. The proper array design is helpful to simplify system structure and signal processing. Com- pared to the traditional narrowband analysis, the antenna array performs some new properties in ultra-wideband （UWB） conditions, which can be used to thin the array. In this paper, an approach is researched for designing linear MIMO array that transmits ultra-wideband stepped frequency waveform, and the corresponding cross-angle resolution, sidelobe level and grating lobe level are derived. The simulation validates the proposed method.