基于DDS雷达数字接收机的设计及其关键技术

Design and Key Technologies of Radar Digital Receiver Based on DDS

采用 DDS与高精度测频技术来实现 AFC,采用由 DDS实现的相参采样时钟电路和中频正交直接采样电路构成正交双通道接收机 ,有效消除或减少了频率漂移等各种不稳定因素和模拟实现时各种因素对系统性能的影响 。

In this paper, AFC is realized with technologies of DDS and high accuracy frequency measurement,quadrature double channel receiver is made up of circuits of IF quadrature sampling directly and coherent sampling clock realized with DDS.The effect of a11 kinds of unstable factors such as frequency shift and the limits placed by analogy circuit is diminished effectively, even eliminated.Meanwhile,the performance of the receiver is improved greatly, for example,the limits on I(improvement factor) and SCV(visibility) placed by traditional receiver are exceeded.Additionally,some practical problems in realizing are discussed.