脉冲步进频率雷达宽带数字接收

根据脉冲步进频率信号的特征，提出了一种新的宽带数字接收方案．通过对回波脉冲串的分组采样和数字正交混频，实现了宽频带的步进频率脉冲信号的频率搬移，显著降低了信号的采样速率和硬件实现的复杂性．通过多级滤波设计和结构优化，简化了处理结构并提高了滤波性能和实时性．该宽带数字接收处理方法从根本上解决了传统的步进频率混频和相干检波模拟电路中存在的寄生调制和I／Q通道幅相不一致的问题．利用QuartusⅡ软件进行了电路设计和时序仿真，仿真结果表明该数字接收机的处理性能可以满足实时处理的要求，有很好的仿真成像结果．

Broadband Digital Reception of Pulse Stepped-frequency Radars

This paper presents a new design scheme for broadband digital reception for pulse stepped-frequency radars. Based on the characteristic of stepped-frequency signals, the echoes of radar pulse chains are grouped and under-sampled with different sampling clocks. With the combination of band limited sampling effect and digital quadrature mixing, the signal frequencies are moved to baseband in order. A digital cascaded low pass filter is used to filter the baseband samples with the optimized configuration. The spurious modulation phenomenon and I/Q amplitude/phase errors, which often occur in analog circuits, are removed by the digital technologies presented here. The receiver design and synthesis procedure performed by Quartus II shows that real-time processing can be ensured with effective computation. Good imaging results are provided.