等效噪声温度高达数十万度的A／D模块，引起了数字接收机性能的深刻变化。在接收机中，不能简单地将它当成一般有源器件处理。文中论证了数字化后雷达接收机所能达到的灵敏度、瞬时动态范围极限性能指标，推导出设计公式和曲线，给出实验验证结果。结果和概念澄清了一些流行的模糊认识，对数字接收机的增益、灵敏度、瞬时动态范围的设计和调试，可按给出的公式、曲线精确地获得。

The performance of a digital receiver will be changed significantly when the equivalent noise temperature of the A/D module rises to hundred thousands degrees. In the receiver, it is not proper to handle the module as a normal active device. This paper analyzes the limit sensitivity and dynamic range performance specification of the digital receiver. It derives the involved design formulas and curves. The experimentally validated results are also given. These results and concepts clarify some popular confused understanding. The gain, sensitivity and instantaneous dynamic range of the digital receivers can by designed and adjusted accurately according to the given formula and curves.

TN851