探讨了雷达数字化接收系统前端放大链与数字A/D模块级联后,接收系统的噪声系数、灵敏度和瞬时动态范围等参数的变化;研究了在工程上接收系统为获得最佳性能,前端放大链与数字A/D模块性能指标的折衷问题,推导了相应的设计公式并给出了实验验证。最后总结了在接收系统前端和A/D性能允许范围内,获得设计师希望得到的接收系统灵敏度和动态范围的方法及设计参考曲线。
The problem of matching between a receiving front-end amplifier chain and a digital A/D converter module is explored in details. Then the limit performances of a receiving system sensitivity and dynamic range are analyzed when the front-end amplifier chain and the digital A/D converter module are interconnected. An experimental test results is presented to demonstrate and compare with our deduction values in theory. Several compromising suggestions on choosing the right gain of an amplifier chain and a proper AD converter are given. Some aspects and referential curves on receiving system design are summarized which is used to obtain the required sensitivity and dynamic range within the available performances of the front-end and the digital A/D converter modules.