相参脉冲雷达中频信号通用采集系统设计

针对相参脉冲雷达中频信号通用采集系统的设计问题,首先阐述了采样率选择的两个约束条件及其物理意义,然后针对通用采集系统无法满足脉间相参条件的问题,提出了两种信号重建算法,并深入分析了算法性能。由于重建算法需要已知触发延迟时间,随后介绍了一种基于TDC的延迟时间测量方法,并推导了TDC器件的测量精度与重建信号信噪比之间的解析关系,为工程应用中选择TDC器件提供了依据。最后介绍了一个基于虚拟仪器技术构建的雷达中频信号通用采集系统,该系统已成功应用于多种雷达中频信号采集。

Design of IF signal acquisition system for pulse coherent radars

The design of pulse coherent radar IF signal acquisition systems is studied.Firstly,the restrictions on sampling rate are addressed and also their underlying ideas.Secondly,two signal reconstruction algorithms are proposed when the sampling rate does not meet the inter-pulse coherent restriction,and then the properties of the algorithms are exploited.Because the time between trigger and sampling is needed by the algorithms,a measurement technique based on TDC is introduced.The exact formula between the measurement precision of the TDC and the signal-to-noise ratio of the reconstructed signal is showed,and it is the formula of choosing the TDC device.Finally,a design example of the generic radar IF signal acquisition system is given.The system is based on the virtual instrument technique,and it is applied to practice successfully in many situations.