基于射频直采的宽带数字采集系统

Wide-Band Digital Acquisition System Based on Direct RF Sampling Method

雷达信号高频宽带化、作战环境复杂化的发展趋势,使采集系统的瞬时带宽和动态范围成为了目标截获的瓶颈问题。限于ADC器件水平,数字采集系统的带宽和采样频率受到很大的限制,直接影响系统指标。采用S/H+ADC的基本架构,提出一种时间交替的宽带数字采集系统,介绍了系统的架构、S/H+ADC二次采样原理以及4GHz带宽采集系统的实验验证。测试结果表明:该采集系统实现了射频信号的直接采样,提高了采集带宽和动态。

Because of wideband and high frequency of the radar signal,and because of the complexity of the electromagnetic environment,the instantaneous bandwidth and dynamic range of signal acquisition become the bottleneck problem for target intercepting. Limited to ADC device,the bandwidth and the sampling frequency of the digital acquisition are greatly limited,which directly affect the system performance. Based on the architecture of the S/H ＋ ADC,A wide-band time-interleaved digital acquisition system is proposed. And the architecture of the system,the principle of the S/H ＋ ADC double sampling and the verification of the 4 GHz acquisition system are introduced. The tested results show that direct sampling RF signal is achieved,and the bandwidth and dynamic range are improved.