Focused on the realization in engineering practice , this paper discussed automotive anticollision radar ' s function requirement , working principle and system design . through summarizing and analysis of its research and development , the paper proposes a new type of secondary centimeter wave automotive anticollision radar that applied on the expressway 本文以现有技术的可实现性为出发点，讨论了汽车防撞雷达的性能要求、工作原理和总体设计等相关问题，总结了国内外汽车防撞雷达的研发状况，在此基础上设计了一种应用于高速公路上的应答式厘米波汽车防撞预警雷达。
2 the fmcw millimeter - wave radar system is introduced . the basic parts of the system and its work principle , as well as the index of it , are discussed in detail . the sae - 100 millimeter - wave anticollision radar system and the anticollision radar used in the industry are also introduced curtly 2简单介绍了fmcw毫米波雷达系统，包括它的测速、测距原理，基本组成与结构和其主要的性能指标，并简单介绍了已研制的sae - 100型毫米波防撞雷达系统和工业用fmcw毫米波避碰雷达系统及防撞雷达的应用。
Considering that : ( 1 ) radar can achieve its basic application of collision avoidance and warning with the only function of ranging ; ( 2 ) under high speed conditions , radar should have lager effective range than that under slow speed , we designed a new easily realizable automotive anticollision radar , which employs centimeter wave and square pulse amplitude modulation 考虑到： （ 1 ）核心的测距功能实现以后，雷达已经能够完成基本的防撞预警； （ 2 ）在汽车高速运行的情况下，防撞雷达的最小可测距范围和最大作用距离应比低速状态下大。本文采用了技术成熟，易于工程实现的厘米波脉冲雷达，以单波束辐射的方式测距。
In recent years , with the rapid development of the millimeter - wave radar technology and the demand of the safety , anticollision radar system is being studied and used widely . the if ( intermediate frequency ) circuit and the digital signal processing are two important parts of it 随着毫米波雷达技术的日益成熟和人们对安全性的迫切需要，近年来，防撞雷达系统得到了深入研究和广泛应用，如自动巡航控制、碰撞报警和防碰撞系统以及有待发展的雷达成像和汽车的自动驾驶系统等。
